Delaying Second AstraZeneca Vaccine May Enhance Immune ResponseBy Jorge Ramos Zwanziger | Mon, 06/28/2021 - 18:31
A longer interval between the first and the second doses of the Oxford-AstraZeneca vaccine (ChAdOx1 nCoV-19) does not compromise the immune response but enhances it, reveals recent research from Oxford University. “A longer delay of up to 45 weeks between the first and second dose of the Oxford-AstraZeneca vaccine leads to enhanced immune response after the second dose,” reads the university’s press release.
The news might be welcome for many countries that had been forced to delay the application of a second dose after supply shortages, which has also been the case for Mexico. A delay between the doses stressed countries and patients, which feared that immunity could be compromised. “This should come as reassuring news to countries with lower supplies of the vaccine, who may be concerned about delays in providing second doses to their populations. There is an excellent response to a second dose, even after a 10-month delay from the first,” said Professor Sir Andrew Pollard, Professor of Pediatric Infection and Immunity and Lead Investigator of the Oxford University trial of the vaccine.
Moreover, a third dose of the vaccine will be well-tolerated and could significantly boost antibody response, according to Associate Professor Teresa Lambe. “A third dose given more than 6 months after the second dose leads to a substantial increase in antibodies and induces a strong boost to the immune response against SARS-CoV-2, including variants,” reads Oxford’s press release. However, further research may be necessary to provide certainty when it comes to the third dose and its impact on immunization.
How About Mexico?
In June 26, Mexico administered 372,031 vaccines against COVID-19 for a total of 30.95 million people who have received at least one dose, according to the Ministry of Health. This represents about 30 percent of the entire adult population in the country. Around 63 percent of all vaccinated people have received two doses.
However, last week there was an 11 percent increase in new cases when compared to the previous week. The Ministry of Health urged citizens to keep taking safety measures and avoid risky behavior. The Ministry also urged people to keep social distancing, constantly wash their hands, wear facemasks properly and avoid large groups of people. This is particularly important as countries like Israel and Chile, with high vaccination percentages, had a recent increase of positive cases.