Vaccines: First time used, but not new
The COVID-19 vaccines developed by Pfizer-BioNTech and Moderna are effective and were developed quickly because funding was plentiful and the techniques had been in the works for many years, said Dr. Joel Tomlinson, Arkansas Department of Health physician specialist in the Outbreak Response section. Tomlinson made his comments in a Facebook Live presentation organized by the Arkansas Education Association Jan. 28. The two-dose vaccines incorporate a new technique using the body’s own messenger RNA processes – unlike typical vaccines that use a dead or weakened virus. The mRNA vaccines instruct human cells to produce part of the spike protein found on the surface of the COVID-19 coronavirus. The material does not enter the cell nucleus. Once cells produce that protein, the body recognizes them as foreign and mounts an immune response, teaching it to repel an invasion by the virus itself. In studies, the Pfizer vaccine was shown to be 95% efficacious in preventing symptomatic disease, and the Moderna vaccine was shown to be 94.1% efficacious, Tomlinson said. Both vaccines were shown to be 100% efficacious in preventing severe cases.
Both vaccines were tested with large, diverse populations. The Pfizer vaccine had a particularly large Hispanic cohort because it was also tested in Argentina and Brazil. After Pfizer rolled out its vaccine, a Centers for Disease Control and Prevention study found 21 cases of severe anaphylactic allergic reactions among the initial 1.9 million doses of the Pfizer-BioNTech vaccine given through Dec. 23, 2020. That’s 11.1 cases for every million doses, which was more than typical influenza vaccinations of 1.3 cases per million doses. All 21 recovered. Other reactions are more common: swollen lymph nodes in armpits, fatigue, headaches, achy muscles, chills. “Those are almost expected things,” Tomlinson said. “I as a doctor will tell you, ‘Yeah, if you have these and they’re not exaggerated or prolonged, that just tells you the vaccine is working.’” Tomlinson said the vaccines were developed quickly, but no steps were skipped in the process. Traditional vaccine development takes up to 15 years, largely because of financial considerations. Pharmaceutical companies must invest as techniques show promise, while universities must apply for grants. This time, federal money was plentiful and immediately available. The mRNA
technique hasn’t been used in previous commercial vaccines, but it’s been studied with other coronaviruses, including the SARS epidemic of 2003 and the Middle East Respiratory Syndrome virus, which appeared in 2012. Tomlinson said the vaccines can be produced faster because they’re being manufactured in labs, not in vitro in cells. Also on the plus side: No live virus enters the body. The disadvantages include the vaccines’ newness, along with the fact that they require very cold storage. Tomlinson said people who have histories of immediate reactions to vaccines or injectable therapies should consult their doctor. The same is true for people who have an immediate reaction to vaccine components including polyethylene glycol. Pregnant and breastfeeding women are not contraindicated from receiving the vaccine, but those situations were not studied in trials, so he recommends consulting their doctors. People who have an anaphylactic reaction to the first dose shouldn’t get the second one. A third vaccine manufactured by Johnson & Johnson is now being distributed. It showed lower rates of preventing all infections than the others, but it effectively prevents severe illness. It also is easier to store and only requires one shot.
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