A new study has been published in the New England Journal of Medicine that confirms previous work on the duration of protection conferred by vaccines against COVID-19. This study included 7,106,982 people who had received the two doses of the vaccine (from AstraZeneca or Pfizer).
They found that in those over 65 years of age, protection against infection decreased 20 weeks after receiving the second dose when compared to baseline protection (38% vs 62%). Similar results were found in the group aged 16 to 64 years, but the decrease in protection was less (44.3% vs 64.8%).
Also at 20 weeks, vaccine effectiveness decreased (although less pronounced) against the probability of death from COVID-19, both in those over 65 years of age (82% vs. 94% at baseline) and in persons 16 to 64 years of age (84% vs. 95%). In general, a trend of more favourable results is observed with the Pfizer vaccine than with the AstraZeneca vaccine.
Is a continuous reinforcement necessary?
Taking these data into account, it seems reasonable to administer a third dose of vaccine 20 weeks after receiving the second one. However, we believe that the way forward should not be to periodically vaccinate the entire population indefinitely, as this could weaken people’s defense system. It seems much more reasonable to develop antiviral drugs that are capable of blocking old and new variants of the coronavirus.
Tests with antivirals against COVID-19
In this sense, the Journal of Molecular Structure has compared the genetic structure of the coronavirus with that of the hepatitis C virus, finding many similarities between both viruses. Since there are powerful FDA-approved antiviral drugs against hepatitis C, it has been studied using a bioinformatic model their efficacy in blocking a coronavirus enzyme (the main Protease) that is essential for its replication.
It has been proven that at least 6 of the antivirals used against hepatitis C, effectively block the coronavirus enzyme and therefore can be useful treatments to cure COVID-19. Given that these drugs are already being used in people with hepatitis C, we believe that trials against COVID-19 should be started as soon as possible to verify their efficacy.