The B.1.1.529 variant of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was first reported to the World Health Organization (WHO) from South Africa on November 26, 2021 (1). This emerging variant was named Omicron and designated as a variant of concern (VOC). This variant has more than 30 mutations on its spike protein. And similar to the Alpha variant, it is associated with an S-gene target failure on a specific PCR assay due to the presence of 69–70 deletions (2). Preliminary evidence suggests an increased risk of reinfection with this variant and high contagiousness (3, 4). The Omicron variant had been reported in 110 countries across all six WHO regions as of December 22, 2021 (1, 2, 5). In addition, the B.1.1.529 variant was thought to have a higher transmissibility rate than other circulating variants (3, 6, 7). More concern has arisen from the questionable whether current vaccines provide adequate protection against this variant (8). A recent study showed a 41-fold decline of the geometric mean titer (GMT) inverse of the plasma dilution required for 50% reduction in infection (FRNT50) with Omicron compared to previous infection with the wild-type virus, with a three-fold reduction in FRNT50 with the mRNA vaccine BNT162b2 (9). However, it is likely that previous infection followed by vaccination, or a booster dose for those completing their primary series, will likely increase neutralization levels that would confer the needed protection against severe disease from the emerging Omicron variant (10). A recent study showed that even with Omicron, the rate of hospitalization was highest among unvaccinated and lowest among those who received a booster dose 0.88% likelihood to escape current vaccines (3, 11, 12).

As new variants emerge, HCWs must continue to serve COVID-19 and non-COVID patients while still fulfilling personal commitments for their families and themselves (13–15). Burnout, emotional exhaustion, mental distress, depression and psychological stress have been linked to HCWs during this pandemic, and research continues to reveal high rates of infection (16). In addition to patient care, HCWs must keep up with any developments in relation to emerging variants and their effects on clinical presentation, management, and measures of prevention—mainly vaccination and infection prevention practices (17, 18). As the Saudi Ministry of Health announced the first case of Omicron variant on Dec 1st, 2021 (19), we undertook this study to assess HCWs' awareness about the SARS-CoV-2 Omicron variant, their worry levels in relation to the different SARS-CoV-2 variants, their perception of the effectiveness of the current vaccines, and other preventive measures to inhibit the spread of the Omicron variant or other future variants, as well as to assess their agreement with mandatory vaccination of the adult population.

A total of 1,285 HCWs completed the online survey. Table 1 shows the participants' baseline characteristics. The majority (64%) were female, and 70.9% aged between 25 and 44 years. The majority were expatriates (62.3%). Regarding their clinical role, 49.8% were nurses and 46.4% were physicians, of whom 24% were consultants. Fifty percent worked in tertiary institutes, while two-thirds worked in the outpatient department (OPD) or general wards.

Almost all (97.9%) of the participants did not recently travel to countries where the Omicron variant has been recorded. Most (71%) HCWs had not been in contact with COVID-19 patients during the last 3 months, while 22.3% of the HCWs had developed COVID-19 previously.

Regarding COVID-19 vaccination, 99.5% had received two doses, and the first dose was divided equally between AstraZeneca ChAdOx1-S and Pfizer vaccines, and 75% of the second dose was of the Pfizer–BioNTech COVID-19 vaccine. Regarding the booster dose, 94.1% either received or planned to receive it once eligible, according to time-based criteria of the local regulations (Table 2).

Table 3 shows the participating HCWs' awareness and knowledge of the available literature concerning certain facts and queries related to the Omicron variant (key answers displayed in brackets). Almost all (93%) the participating HCWs knew that the Omicron variant was first described in South Africa; however, 81.7% believed that the Omicron variant was already reported in Saudi Arabia. Of the respondents, 66% knew that Omicron variant is more transmissible than the Delta variant, while 26.7% were not sure. The majority (71.8%) did not know that the Omicron variant spike protein has 22 mutations. Still, 56.2% expected that Omicron variant causes similar signs and symptoms to the original variant. Most (85.1%) of our cohort were aware that SARS-CoV-2 mutations are expected, while they were almost equally divided regarding their opinion on whether they were unsure or whether the Omicron variant may/may not cause more severe disease compared to previous variants. About half of the participants were unsure if mRNA or vector-based vaccines are effective against the Omicron variant. At least two-thirds of them were unsure if therapeutics such as monoclonal antibodies used against previous variants might be effective against the variant.

The mean participants' self-rated familiarity with the Omicron and Delta variants of the SARS-CoV-2 virus was 3.24 (SD 0.95) and 3.5 (SD 0.99), respectively, with strong and significant correlation between these scores p < 0.0001 (t = 6.7928, df = 2,568). When we explored the participants' sources of information about the Omicron variant, the MOH and WHO websites were the main sources, but social networks were also used to obtain information in equal measure (about 50%), followed by Official statements (41%), hospital announcements (38%), and the Center of Disease Control (CDC) and Saudi CDC websites, which were accessed almost equally (between 30 and 33%), while scientific journals were lower down on the list (28.7%).

Of the participants, 66.9% agreed with the vaccine's effectiveness to prevent the spread of Omicron or other future variants, while when considering other preventive measures, such as universal masking, social distancing, and avoiding unnecessary international travel, their agreement was higher (77.8, 78, and 71.4%, respectively). Participating HCWs (82.2%) felt that the COVID-19 vaccination should be mandatory for all eligible adult populations, while only 5.1% disagreed (Table 4).

Almost half (42.7%) of the HCWs perceived that any of the current mRNA vaccines (Pfizer–BioNTech COVID-19 vaccine or Moderna COVID-19 vaccine) would be the best COVID-19 booster vaccine, while 26.9% felt that a newly developed mRNA vaccine that would better target the Omicron variant is best, and 26.2% agreed to receive any of the available vaccines as a third booster dose (Table 4).

Regarding the participants' perceived risk from the Omicron variant, 16.9% felt that patients with immune deficiencies are at the highest risk, followed by the elderly (14.9%), HCWs (14.1%), and then patients with chronic medical illnesses (Table 4).

When assessing the participants' perceptions about future perspectives of the Omicron variant locally and internationally, 57.7% agreed that it has the potential to cause a new COVID-19 pandemic wave worldwide, while only 45.9% agreed that it may cause another COVID-19 wave in Saudi Arabia, and 46.1% agreed that it may cause a lockdown (Table 4). The current cohort of HCWs had the highest worry level in relation to international travel (3.19, SD 1.12), followed by the Omicron variant (2.18, SD 1.14), and their worry levels in relation to the original SARS-CoV-2 and Delta variants were comparable (1.96, SD 1.14 and 1.97 SD, 1.13, respectively), while their worry level in relation to the Alpha variant was the lowest (1.67, SD 1.1).

This study explored HCWs' perceptions and awareness of the SARS-CoV-2 Omicron variant after the initial WHO alert, in addition to their agreement with vaccine effectiveness to prevent its spread or other potential future variants. Most (64%) respondents were female, similar to a previous study about Delta variant concerns in KSA. This was also in agreement with other studies showing that the majority of HCWs are female (24–26).

One-fifth of study participants received a booster dose, while the majority reported plans to receive it once they became eligible, with a small percentage (6%) not planning to receive it. The majority (69.6%) in our study chose to receive the booster dose with any of the currently available mRNA vaccines or newly developed ones; this observation mirrors another study conducted in a neighboring country among HCWs, where they also preferred mRNA vaccines (27). Such behavior could be partly due to the hematological side effects that have been recorded with the viral vector vaccines (27). In addition, this could signal vaccine selectivity (VS), which is currently an emerging public health challenge due to the multiplicity of vaccine options. Another explanation is vaccine hesitancy (VH), which could be related to reliance on social media as the main source of information, which was reported by almost half of the participants, as opposed to less than one-third who reported utilizing scientific journals as a main source of information; therefore, increased access to peer-reviewed journals should be strongly encouraged among HCWs (24). Keeping in mind the double edge sword effects the social media plays on individuals' decision making, as social media spreads information that's not scientifically always verified, puts their personal touch or psycho-cognitive flavor that drives the audience, therefore our observation of social media being highly used source of information by the surveyed HCWs can explain some observations like (VS), (VH) and HCWs significant agreement with mandatory vaccination for all adults. Such agreement might be a reflection of their self-rated familiarity level with the Omicron variant (stemming from the information they acquired from social media) that also correlated significantly with their agreement with mandatory vaccination. Social media spread with the emergence of the Omicron variant a huge load of information that was potentially driving all sectors of the society to abide with all the measures of protection including vaccination, from SARS-CoV-2 including its new Omicron variant.

The primary concerns regarding Omicron are whether it is more contagious, more virulent, or both, in comparison to other variants, and how likely it would be to evade natural (post previous COVID-19 infection) and vaccine-induced immunity (3, 28–30). However, with more than 30 mutations and some deletions that are similar to other variants, increased transmissibility and higher antibody escape were expected (31). However, with few clinical and epidemiological data to help define the true threat of Omicron, participants' mixed knowledge responses are expected, as has been observed in our study, in which they even extended to their belief in the effectiveness of the vaccines to control its spread (32).

Among our study participants, regarding the perceived effectiveness of various methods to control the spread of the Omicron variant, social distancing and universal masking scored the highest, followed by avoiding international flights and, lastly, vaccination. Again, such observations shed light on their questioning of the vaccine's effectiveness against Omicron due to its many mutations, especially involving the spike protein. Their perceived effectiveness of the current COVID-19 vaccines against the Omicron variant was 67%. This represents a decline in HCWs' perception of vaccine efficacy compared to our earlier study, performed in December 2020 during the initial rollout of the COVID-19 vaccines, which was 80.2% (33). Such findings reflect declining confidence in vaccine efficacy against emerging variants, which is noteworthy since their concerns about efficacy have been stated as one of the main reasons for vaccine hesitancy (34). COVID-19 vaccine-related uncertainty and challenges persist in the face of combacting emerging SARS-CoV-2 variants. Immune escape is a real concern with the Omicron variant. According to findings from South Africa, the efficacy of the Pfizer-BioNTech vaccine against the Omicron variant was significantly reduced, with a 41-fold lower level of neutralizing antibodies when compared to the wild-type variant of SARS-CoV-2 (10).

The fact that 82.2% of HCWs agree with mandatory COVID-19 vaccination for all adults is an interesting finding. Mandating immunizations for HCWs or other business employees is not only ethical, but also legal. Employers have the right to require vaccination as a condition of employment, as the Equal Employment Opportunity Commission and courts have stated (35) and a multi-society statement on COVID-19 vaccination had been also released (36). This right applies to both vaccinations approved for emergency use and those that have been fully approved by the FDA. Mandates, however, can erode public support, causing a backlash and even lowering vaccine uptake. There are no established processes to enforce population-wide vaccination obligations in most countries, despite the fact that employers, healthcare providers, and educational institutions can monitor compliance with mandates. Requiring COVID-19 immunizations for HCWs, for example, is not a new practice; rather, it is a continuation of a long-standing policy. Vaccination against influenza, hepatitis B, and other infectious diseases has long been mandatory in many health-care settings (37). Whether to mandate COVID-19 vaccination for HCWs and/or all employees and how to implement such a policy is ultimately a local authority decision. For instance, the local authorities in both New York and California announced a vaccine mandate for state employees (38).

We observed that HCWs' beliefs in infection control measures that have been mandated and optimized during the COVID-19 pandemic namely, universal masking, social distancing, and vaccination as preventive methods for the spread of the Omicron variant or other future variants (39, 40) all correlated positively and significantly with their belief in mandatory vaccination for all eligible adults. They still believed that avoiding unnecessary international travel is an effective measure in preventing the spread of SARS-CoV-2 variants, even after widespread vaccination, perhaps due to the emergence of at least three variants, one of them with high transmissibility and serious clinical morbidity and high mortality (the Delta variant). However, there is a huge consequence of travel ban and lockdown with any emerging variant (41, 42).

HCWs who believed that SARS-CoV-2 mutations are expected and will reoccur were significantly less in agreement with the belief that the vaccines are ineffective against the spread of the Omicron variant or other potential future variants, which is an expected and healthy belief, as the best preventive measure to contain the pandemic at present is widespread vaccination This has been observed in HCWs' stringent behavior of abiding by the infection prevention measures, such as universal masking and social distancing, for the same purpose (39, 40), which has also been observed in our results, in which agreement with the effectiveness of vaccination to prevent the spread of mutant variants is significantly and positively associated with agreement with mandatory vaccination.

HCWs in critical care areas believed significantly in the ineffectiveness of the vaccines to prevent the spread of mutant variants, including Omicron. This might be explained by the multiple mutations that the Omicron variant has and the critical care workers' anxiety regarding the current vaccine's efficacy against it, being frontlines exposed to severe cases. In the same vein, we observed that HCWs who relied on the WHO as a main source of information disagreed with the vaccine's effectiveness to prevent the spread of the mutant strains, including Omicron, as it is a scientific source that releases only evidence-based information, which has not thus far proven the vaccine's efficacy in that regard.

Male gender was significantly associated with agreement with mandatory vaccination of all eligible adults. This attitude has been observed in multiple studies, as males were more inclined toward vaccine uptake and had much less vaccine hesitancy, while age did not correlate with mandatory vaccination agreement (27, 43).

The level of agreement with the effectiveness of vaccines to prevent the spread of mutant variants was significantly associated with agreement with mandatory vaccination, and the same was observed with the level of agreement with the belief that there might be a second national lockdown due to the Omicron variant. This behavior from HCWs—of stringent abidance with vaccination—correlates with their expectation of its effectiveness to prevent the spread of any mutant variant, and their fear of a national lockdown, not unexpectedly, drove them to have an unwavering belief in mandatory vaccination as the best modality to prevent it. However, they did not perceive the effectiveness of unnecessary travel avoidance to be effective in preventing the spread of mutant variants or being superior to mandatory vaccination. Early lockdown and social distancing in the initial phase of the pandemic were useful in slowing the spread of SARS-CoV-2 in Saudi Arabia (44). In addition, during the peak of the initial lockdown the level of anxiety was associated with being with family members at risk of SARS-CoV-2 infection. Thus, it is understandable that HCWs fear the occurrence of second lockdown with the emergence of the Omicron variant (45).

This is the first national survey in Saudi Arabia that was conducted in the first week of the WHO Omicron variant announcement, to address HCWs' awareness of the variant, acceptance of vaccine booster doses and agreement with vaccination to prevent the spread of SARS-CoV-2 Omicron variant or future variants. Only about two-thirds of HCWs perceived that vaccination is the best option to prevent the spread of the Omicron variant, indicating the need for future studies to explore the performance of currently available vaccines in terms of the protection they offer against the current variants. At the same time, the HCWs had a strong belief in preventive measures, such as universal masking and social distancing, to prevent the spread of Omicron or future variants, which should still be maintained in practice, at least in healthcare institutions, to prevent nosocomial spread until further evidence can be elucidated.

The original contributions presented in the study are included in the article/supplementary materials, further inquiries can be directed to the corresponding author.

The studies involving human participants were reviewed and approved by IRB, King Saud University, Riyadh, Saudi Arabia. The patients/participants provided their written informed consent to participate in this study.

M-HT, SAle, MA, FAlj, KA, FAlz, SAls, MB, ZM, and JA-T conceptualized the study, analyzed the data, and wrote the manuscript. RA, RB, FAls, AAlr, AAlh, AAla, NAl, RH, LA, NAb, AJ, AF, AA-E, and WA contributed to the study design, collected, analyzed, interpreted data, and edited the manuscript. All authors reviewed and approved the final version of the manuscript.

This project was funded by Princess Nourah Bint Abdulrahman University researchers supporting project (number PNURSP2022R21) Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.