A large-scale study has shown that two doses of the Pfizer/BioNTech covid vaccine are extremely effective in preventing hospitalisations for at most six months. However, the protection against infection is almost half as effective over that time.
According to research, the effectiveness against all Covid infections dropped from 88% after one month of receiving two doses to 47% six months later. However, the overall effectiveness against hospitalisations was still high at 90% and across all variants including delta.
These findings were published in Lancet and are consistent with preliminary reports by the US Centers for Disease Control and Prevention and Israel's ministry of Health that indicated protection against the virus would fade within six months.
Researchers said that the results highlight the critical importance of increasing Covid vaccination rates worldwide.
The UK's NHS offers booster jabs to those who have had their second vaccination at least six months ago and are residents in residential care homes for the elderly, over 50 or social workers.
It invites 16-to 49-year olds with underlying medical conditions that could lead to severe symptoms, as well as adults who have had contact with immunosuppressed people in their homes, to receive their third vaccine.
The study's lead author, Dr Sara Tartof of Kaiser Permanente Southern California Department of Research and Evaluation, stated that vaccines are an important tool in controlling pandemics and still prove highly effective in preventing severe illness and hospitalisation.
Researchers analyzed the health records for three million people from December 2020 to August 2021. 5.4% of the people infected by SARS-CoV-2 were found to have been infected during the study period. 6.6% of those infected were admitted to hospital. It took between three and four weeks for all infected to be fully vaccinated.
Dr Luis Jodar is senior vice-president of Pfizer vaccines and chief medical officer. He stated: Our variant-specific analysis clearly demonstrates that the BNT162b2 vaccination is effective against all variants of concern, even Delta. Covid-19 infections in patients who have had two doses of vaccine are most likely due waning, and not because of other variants that escape vaccine protection.
Penny Ward, a visiting professor in pharmacy medicine at Kings College London, was not part of the study. She said: This publication presents real-world evidence in the USA on the effectiveness and safety of the Pfizer/BioNTech vaccination. It is based on data from the Kaiser Permanente healthcare database.
If the goal of vaccination is to prevent disease and stop the spread of infection, then boosters are necessary six months after the completion of the first course. This information applies especially to the most vulnerable who may be at greater risk of serious illness or death. The UK has adopted this approach and is currently launching a booster campaign.
Nursing leaders warn that there is a possibility of an increase in infections this winter. They also fear that more nurses may become sick from anxiety and depression. This could impact patient care.
The Royal College of Nursing examined data on staff sickness before and after the pandemic, and discovered that thousands of days were lost due to staff absences on already stretched wards.
In May 2021, the NHS England saw a rise in 18% in the number of sick days for nurses and health workers. This was compared to May 2019. The analysis revealed that staff are more susceptible to mental health issues, chest and respiratory problems, and migraines now than they were before the pandemic.
The number of days lost to mental health has increased by 31.4% since May 2019 from 102,491 in 2019, to 134,669 2021.
Carol Popplestone (chair of the RCN councils) stated that there will be tremendous pressure on health care services this winter. Services can't afford to lose safety critical professionals to preventable illnesses. This is on top of the tens of thousand of nursing vacancies.
