Is the COVID-19 vaccine better at longer injection intervals?

Was the COVID-19 vaccine administration schedule a little wrong? This is asked when experts at the U.S. Center for Disease Control and Prevention are trying to convince health officials to inject more vaccine-eligible holdouts (about one in five Americans) this month. I have a question.

The vaccine given has a significantly lower risk of COVID-19 infection, severe illness, and death, but with rare but severe side effects of heart inflammation and diminished protection that prompted the promotion of a third booster. And effectiveness questions are hampering acceptance. ..

CDC experts said on February 4, Pfizer and Moderna’s most widely used US vaccine would be effective if given twice at 3-4 week intervals and boosted 5 months later. He presented his advisor with evidence that the first two doses were safe. Instead, it is given every 8 weeks. The CDC has not yet made a decision on the shot interval, and it is unclear when the issue will be addressed again.

One important question is whether changing the dosing schedule makes the vaccine more reliable or weaker.

Other countries, including Canada, the United Kingdom and India, have separated the two shots further for some time, and Los Angeles emergency physician and medical consultant Dr. Michael Daignault can ease concerns about shots in the United States. It states. The same is true for states.

Daignault has confirmed that after the second injection, the CDC officially recognizes the “value of extended interval dosing” in both improving the immune response and reducing the “already low risk of myocarditis or heart inflammation.” I called it a “major change.” He and Dr. Monica Gandhi of the University of California, San Francisco said in a letter last week that it would be both “a shift in the country’s seismic policy” and “a long postponement.”

Other countries that decided to lengthen the gap between doses were limited by putting more limited protection from the first shot into as many arms as possible before giving the second shot. I was trying to get the most out of my vaccine supply. society.

According to a Canadian and UK CDC study summary, vaccine efficacy against infection and hospitalization was 5-10% higher with a 7-8 week interval between primary shots than the standard 3-4 weeks. Neutralizing antibody titers (antibodies that fight infection, blood levels of proteins that destroy disease-causing viruses and bacteria) also increased after long dosing intervals of 6-14 weeks. The data also showed that the longer the intervals between shots, the lower the risk of heart inflammation.

Canada has adopted an eight-week interval between shots, and England has at least an eight-week interval for teens and adolescents.

CDC Dr. Sara Oliver In this month’s presentation Examination of longer dosing intervals may be convinced by evidence that the risk of heart inflammation is higher and the safety and efficacy of the vaccine is even higher, about 33 million unvaccinated people aged 12-39 years. Is targeted.

The CDC review did not cover the Johnson & Johnson vaccine. Two months later it was given as a single shot with a booster. Also, it is not clear how improved protection by increasing the spacing between Pfizer shots or modeler shots will affect the need for a third booster shot.

Pfizer introduced a question about the idea of ​​extending the dosing regimen to the CDC, and Moderna did not comment.

Dr. Oliver also said that longer dosing intervals have potential downsides. People who receive only one vaccination every eight weeks have less protection against illness during that period and are not considered “fully vaccinated” and can affect their condition at work or school. There is sex. For the elderly and those at medical risk, longer intervals that remain more vulnerable to infection may not be ideal.

Still, Gandhi and Dyno argue that this concept is worth further discussion, and they and other physicians are already strongly considering increasing the interval between first and second doses to their patients and their families. He states that he is advising. They said that only the rabies vaccine would be given at intervals of only 3 weeks.

“For millions of Americans who are unvaccinated and overwhelmed by the difficult task of having to get the latest vaccine three times, extending the interval is more appealing, You can relieve your hesitation, “they insisted in a letter.

But Dr. Robert Quigley is not convinced.

Quigley, an immunoscientist, cardiac surgeon and global medical director at International SOS in Pennsylvania, says vaccines given in the United States have already been shown to be overwhelmingly safe and effective. .. He said that longer dosing schedules may have some additional benefits, but any changes in managing them can undermine credibility.