The approved vaccines against the SARS-CoV-2 virus have proven to be very effective in fighting the pandemic, but were developed early, before new strains were introduced. Some of these strains have the ability to overcome the immunity afforded by vaccines.
The doctors of the Therapeutic Clinic of the Kapodistrian National University of Athens Theodore Psaltopoulou, Panos Malandrakis, Yannis Danasis and Thanos Dimopoulos (Rector of EKPA) presented the analytics, taking into account the latest data.
A recent study, published in the international journal Lancet, evaluated the effectiveness of the AstraZeneca vaccine against the new Delta strain.
ASTRA ZENECA (AZD1222), almost all participants (55/63, 87%) had neutralizing antibodies against strains D614G (original strain) and B.1.1.7 (British strain). A significantly smaller number of vaccinated persons had neutralizing antibodies against B.1.351 (Beta strain, South Africa) with an indicator of 38/63, 60%, and B.1.617.2 (Delta strain, India), 39/63, 62%. In contrast, more than 95% of those vaccinated with two doses of Pfizer vaccine (BNT162b2) developed neutralizing antibodies to strains Beta and Delta.
In conclusion, the researchers note that vaccinated ASTRA ZENECA have a lower antibody response to SARS-CoV-2 than Pfizer, which is consistent with both clinical trial data and recently published data from the United States.
A recent publication by A. Choi and a group of researchers analyzed the ability to neutralize strains of SARS-CoV-2.
Researchers collected serum vaccinated with two doses of Moderna vaccine one week after the second dose of vaccine and tested the neutralizing ability in the laboratory. Complete vaccination resulted in the development of neutralizing antibodies against all strains such as Beta (B.1.351, South Africa), Delta B.1.617 (India), Kappa (B.1.617.1), Ita (B.1.525, Nigeria), A .23.1 (Uganda) and A.VOI.V2 (Angola).
The above data show that it is important to complete the full vaccination program with both doses of AstraZeneca, Pfizer and Moderna vaccines as they provide protection against the newer SARS-CoV-2 strains. Today in Greece, about 50% of Greeks have received at least the first dose of the vaccine, and 36% have completed the vaccination.