Currently there’s limited information on how effective is the mRNA vaccine will be against the newly emerged strains of COVID-19.
List of abbreviations:
o Sms: Symptoms
o aSmtic: asymptomatic
o NPS: nasopharyngeal swab
o AB: Antibody.
Currently there’s limited information on how effective is the mRNA vaccine will be against the newly emerged strains of COVID-19. Both clinical trials preceded the recognition of the major variant (s) observed now in many countries worldwide. Preliminary trials (not peer reviewed & not published) suggest that vaccine might be more protective against some of the viral variants than others. Crucial limitation of these data (using laboratory sampling from immunized or recovered subjects to evaluate neutralization) is that protection offered by vaccination is more complicated than simple assessment of AB titers. Viral molecular sequence from incident ptns with COVID-19 seen after vaccination will be crucial to help explain this important issue. Practically, discovering these viral variants would not alter our basic recommendations regarding vaccination. Particularly wise, it is not advised that people should wait for a newly provided or altered vaccine hoping that it will be more efficacious against the newly emerged COVID-19 variants.
Many commentaries on the results of the vaccine clinical trials cite a lack of information on asymptomatic infection as a limitation in our knowledge about the vaccines’ effectiveness.
Actually, theoretically, as almost FORTY % of subjects with COVID-19 infection have no Sms but may still transmitting the virus to other subjects. So, until enough data whether the vaccine protects against aSmtic infection, we should keep emphasizing to our ptns that vaccination does NOT permit omitting other vital measures preventing the spread of COVID-19. We are in true need to persist
o Social distancing,
o keep masking,
o Prohibiting over crowded indoor situations, &
o Continuous hand washing.
Several factors, indeed allow us to be optimistic regarding the vaccine’s impact on viral transmission. First, in the “Moderna trial”, subjects underwent NPS PCR testing at the baseline and repeated after four weeks, with returning for the 2nd dose. Among -ve subjects at baseline and with no Sms, 0.3% in placebo g. & 0.1% in mRNA-g. had +ve NPS for COVID-19 by PCR at the 4th week. These results suggest that even single dose, vaccine can protect and prevent aSmtic infection.
Second, findings from population-based trials are suggesting that subjects with no Sms are less likely for viral transmission to others. Third, widely used vaccines are currently offering powerful protection against both disease & its transmission, so much so that infection control policy is currently the main motivator behind vaccine policy. However, certain vaccines may permit aSmtic colonization that could be applied also to COVID-19 vaccine. In addition, the protective umbrella will never be completely 100% that explains the higher number of cases, and recommending social distancing & masking in the community still validated. However, the possibility that vaccines still limiting the capacity of viral transmission to other individuals still excellent.