Studies in Brazil and Sweden have shown that vaccinating people who have recovered from the new coronavirus (COVID-19) increases protection and reduces the risk of becoming sick enough to require hospitalization or death if re-infected.
Both research teams published their research on March 31.
The Brazilian study looked at 22,566 people who had recovered from Covid-19.
The team found that vaccines provided significant additional protection for recovered patients, whether they received Sinovac, AstraZeneca, Johnson & Johnson, or Pfizer.
India's new crown pneumonia epidemic: The picture shows on March 25, 2022, students in Ahmedabad, India are vaccinated against the new crown.
(AP)
Effectively prevent death
After 14 days of vaccination, the Sinovac vaccine provided the lowest additional protection and the Pfizer vaccine provided the highest additional protection.
The effective rate of Sinovac vaccine to prevent re-infection is 39.4%, and the effective rate of Pfizer vaccine to prevent re-infection is 64.8%
The Sinovac vaccine was 81.3% effective in preventing hospitalization or death, and the Pfizer vaccine was 89.7% effective in preventing hospitalization or death.
The Kexing vaccine was developed by China Sinovac; the AstraZeneca vaccine was jointly developed by the British pharmaceutical company AstraZeneca and the University of Oxford; the Johnson & Johnson vaccine was developed by the American Johnson & Johnson; the Pfizer vaccine was developed by the American Pfizer and German Biopharmaceuticals Collaborative research and development of new technology company BioNTech.
New crown pneumonia epidemic in the United States: The picture shows that on January 31, 2022, medical staff in Chicago, the United States treat a new crown pneumonia patient in the intensive care unit of the hospital.
(Getty)
Protection lasts at least 9 months
The Swedish study analyzed data on more than 5 million people.
The team found that the "mixed immunity" obtained by contracting the new coronavirus and getting one or two doses of the vaccine provided additional protection against re-infection for at least nine months.
Compared with natural immunization, recovered patients can obtain an additional 94% protection after a dose of the vaccine, preventing the disease from becoming severe enough to require hospitalization.
After two doses of the vaccine, recovered people can get an additional 90% protection against getting sick enough to require hospitalization.
Study excludes Omicron recoverers
Both studies were published March 31 in the British medical journal The Lancet Infectious Diseases.
The study subjects of the above two studies also did not include recovered patients who had experienced first or re-infection with the new coronavirus variant strain Omicron (Omicron).
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