Regular physical activity may boost the effectiveness of the COVID-19 vaccine, according to research done by Discovery Vitality, which showed that a combination of regular exercise and vaccine independently helped ward off severe infections, including reduced hospital admissions and a smaller risk of ICU admissions, ventilation and death.
The study, published in the British Journal of Sports Medicine, also reveals that the level of protection against serious infection improves in tandem with the amount of exercise done.
The publication of the study comes amid an increasing number of positive COVID tests, and rising amounts of COVID-19 RNA being found in wastewater systems countrywide.
The latest National Institute for Communicable Diseases (NICD) report on the presence of COVID-19 genetic particles in the country’s wastewater shows that virus levels are high to intermediate, with some increases over the past week in plants tested by the NICD in Gauteng, eThekwini and Mangaung.
Omicron dominant
The most recent sequencing report by the Genomic Surveillance Network shows Omicron is still the most dominant variant in circulation, and specifically the BA.5 subvariant. BA.2.12.1, another subvariant that has proven adept at escaping immunity, was detected in South Africa at low prevalence in May, June and July. Samples of XAY, another subvariant in the Omicron family, were also found in small amounts.
New cases
Since last week, 2 327 new cases of confirmed infections have been reported, reports Daily Maverick. There was a 5.7% decrease in the number of new cases detected since the previous week, but incidence risk in Gauteng and the Western Cape remains above the levels designated safe by the World Health Organisation.
Gauteng reported the highest weekly incidence risk (7.1 cases per 100 000 people), followed by the Western Cape (6.3 cases per 100 000). For an outbreak to be under control, this should be lower than five, according to the WHO. A smaller number of COVID-19 PCR tests were done in the past week, according to the latest test results from the NICD.
On average, 9.8% of tests in South Africa are positive for the virus at present, with the highest positivity rate in Limpopo (15.3%) followed by Gauteng (13.7%).
Exercise and vaccination
The Discovery Health and Vitality study was conducted in collaboration with the Witwatersrand Sport and Health Research Group, the Sisonke Programme and the South African Medical Research Council (SAMRC).
The research shows the improved effectiveness of the Johnson & Johnson single-dose vaccine with increased physical activity levels.
Discovery Health’s chief healthcare analytics actuary, Shirley Collie, says: “We set out to test the hypothesis that regular physical activity enhances the immune-boosting effect of vaccines, reducing severe outcomes in vaccinated people (measured by hospital admission).”
The study used data of health workers who had signed up for the Sisonke study, providing early access to the J&J vaccine, and who were also members of a medical aid administered by Discovery and members of the Vitality Wellness programme.
It was the first study of its kind using recent, directly measured physical activity data to demonstrate an association between increased levels of regular physical activity and the effectiveness of vaccination against adverse COVID outcomes.
Those who were fully vaccinated and who reported high weekly levels of physical activity were nearly three times less likely to be admitted to hospital than those vaccinated, but with low physical activity.
While fully vaccinated people had their risk of hospitalisation reduced by 60%, those who were also active saw reductions of between 72% and 80%, depending on their levels of exercise.
“Ours is not the first study of this nature. Past studies that have measured antibody responses to determine vaccine efficacy (looking at vaccines like the flu vaccine) suggest that regular physical activity of moderate intensity enhances the protective effect of vaccines, especially in those with immune dysfunction, including the elderly,” Collie said.
Professor Jon Patricios from Wits Sport and Health says: “This substantiates the WHO recommendations for regular physical activity; namely, that 150-300 minutes of moderate to high intensity physical activity a week will have meaningful health benefits in preventing severe disease, in this context against a communicable viral infection.”
The benefits
Professor Glenda Gray, president of the SAMRC, cautions that more research is needed to understand why exercise enhances vaccination’s effects.
“For now, we suggest this may be a combination of enhanced antibody levels, improved T-cell immunosurveillance and psychosocial factors,” she said.
Study details
Association between regular physical activity and the protective effect of vaccination against SARS-CoV-2 in a South African case–control study
Shirley Collie, Robin Terence Saggers, Rossella Bandini, Lizelle Steenkamp, Jared Champion, Glenda Gray, Linda-Gail Bekker, Ameena Goga, Nigel Garrett, Jon Patricios.
Published in the British Journal of Sports Medicine on 27 September 2022
Abstract
Background
Both vaccination and physical activity have been shown to independently decrease the likelihood of severe COVID-19 infection.
Objective
To assess the association between regular physical activity and vaccination against COVID-19 among healthcare workers.
Methods
A test negative case–control study design was used to estimate the risk of having an associated COVID-19-related hospital admission, among individuals who were unvaccinated compared with those who were fully vaccinated with Ad26.COV2.S (>28 days after a single dose). 196 444 participant tests were stratified into three measured physical activity subgroups with low, moderate and high activity, to test the hypothesis that physical activity is an effect modifier on the relationship between vaccination and hospitalisation.
Results
Vaccine effectiveness against a COVID-19-related admission among vaccinated individuals within the low activity group was 60.0% (95% CI 39.0 to 73.8), 72.1% (95% CI 55.2 to 82.6) for the moderate activity group, and 85.8% (95% CI 74.1 to 92.2) for the high activity group. Compared with individuals with low activity levels, vaccinated individuals with moderate and high activity levels had a 1.4 (95% CI 1.36 to 1.51) and 2.8 (95% CI 2.35 to 3.35) times lower risk of COVID-19 admission, respectively (p value <0.001 for both groups).
Conclusions
Regular physical activity was associated with improved vaccine effectiveness against COVID-19 hospitalisation, with higher levels of physical activity associated with greater vaccine effectiveness. Physical activity enhances vaccine effectiveness against severe COVID-19 outcomes and should be encouraged by greater public health messaging.
NICD COVID report (Open access)
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Regular physical activity a strong protection against severe COVID-19
New dashboard lets public track COVID levels in local sewerage systems
J&J booster 84% effective against hospitalisation — Sisonke 2
SAMRC: Rising levels of SARS-CoV-2 RNA fragments in Tshwane and NMB wastewater