The Oxford University study found that the longer the interval between Pfizer vaccine doses, the higher the overall antibody level.
A study in the United Kingdom found that the longer gap between Pfizer’s COVID-19 vaccine doses resulted in higher overall antibody levels than the shorter gaps, but the antibody levels would not last long after the first dose.
Research led by the University of Oxford may help inform vaccination strategies against Delta variants. Although the two doses of the vaccine still have a protective effect, it will reduce the effectiveness of the first dose. The weekly gap is the “sweet spot” vs. Delta Air Lines.
“We found that, on average, if your dosing interval is shorter, your antibodies will decrease,” Susanna Dunachie, professor of infectious diseases at the University of Oxford and co-lead researcher of the study, told Al Jazeera .
“But it’s at the population level, so I think the first thing I want to say is that two doses of Pfizer vaccine are very good at inducing immune responses. If you have been vaccinated with Pfizer vaccine in a short period of time, please don’t worry, it’s a very good one. Vaccine.”
The author emphasized that in a study of 503 medical staff, any of the dosage regimens produced strong antibody and T cell responses.
The author of the study said: “For longer dosing intervals…after a single dose, the neutralizing antibody level against the Delta variant is not well induced and cannot be maintained during the interval before the second dose. “
“After two vaccinations, compared with the shorter dosing interval, the neutralizing antibody level is twice as high after the longer dosing interval.”
Neutralizing antibodies are believed to play an important role in immunity against coronavirus, but not all of them. T cells also play a role.
The study found that compared with the short dosing interval of 3-4 weeks, the overall T cell level is 1.6 times lower and the interval is longer, but a higher proportion is “helper” T cells, which support long-term immune memory, which is far from the long gap. .
“Although we tend to emphasize neutralizing antibodies as a measure of immune response… Cellular immunity, which is difficult to measure, may also be very important,” said Peter English, former public health chairman of the British Medical Association (BMA) . Medical Committee.
The results of the study published as a preprint support the view that although a second dose is required to provide comprehensive protection against Delta, delaying that dose may provide longer-lasting immunity, even at the cost of short-term protection.
“We found that the UK’s strategy is to provide a longer dose strategy, which is based on knowledge of vaccines for other diseases, and longer intervals are usually better, and it is also a way to quickly stab as many people as possible with one dose-in fact Eventually higher antibody levels were produced,” Dunaki told Al Jazeera.
In December last year, the United Kingdom extended the vaccination interval to 12 weeks, but Pfizer warned that there is no evidence to support getting rid of the three-week interval.
The UK now recommends an eight-week interval between vaccine doses in order to provide more people with a high degree of protection against Delta faster, while still maximizing the immune response in the long term.
