With current licenced vaccines, the key objectives of COVID-19 vaccination remain the reduction of severe sickness and death as well as the protection of the healthcare system from the virus.
All variants, including Omicron, can be protected against severe illness outcomes by using presently licenced vaccines based on the index virus (i.e., the virus that was isolated from the initial cases of COVID-19 in December 2019).
New variations of SARS-CoV-2 are expected to arise in the future, particularly those with modifications to the spike protein, as the virus continues to evolve since it debuted late in 2019. The genetic and antigenic properties of future SARS-CoV-2 variants cannot be predicted at this time.
Since we don’t know what the future holds, we should aim for additional benefits from COVID-19 vaccination, such as protection from milder forms of the disease as well as new strains.
According to the data that are currently available, it appears that the inclusion of Omicron, which is the SARS-CoV-2 Variant of Concern that is the most antigenically distinct, in an updated vaccine composition may be beneficial if it is given as a booster dose to individuals who have already received a COVID-19 vaccination primary series.
Omicron variations can be protected from severe illness consequences by using presently licenced vaccines based on the index virus, with a booster dose. As a result, to meet the fundamental objectives of COVID-19 vaccination, it is reasonable to continue using existing licenced vaccines for primary vaccination and as a booster dose.
It may be prudent, given the uncertainty of future SARS-CoV-2 genetic and antigenic characteristics, to pursue an additional goal of COVID-19 vaccination to achieve a wider antibody response against circulating and emerging variants, while maintaining protection against severe disease and death.
COVID-19 Omicron, the most antigenically different SARS-CoV-2 VOC, may be useful in an updated vaccine composition, according to the existing evidence. Those who have already had a primary series of COVID-19 vaccinations would be best served by a booster dose of this if such vaccines were made accessible.