Regular physical activity may boost the effectiveness of the Covid jab, according to research done by Discovery Vitality and published in the British Journal of Sports Medicine.

The study 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 Covid tests coming back positive, and rising amounts of Covid-19 RNA being found in wastewater systems countrywide.

According to the latest National Institute for Communicable Diseases (NICD) report on the presence of Covid-19 genetic particles in the country’s wastewater, levels of the virus 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 latest 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. 

The subvariant, dubbed Centaurus, had even more mutations to help it escape previously acquired immunity.

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 were reported.

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 Organization. 

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.

Evidence produced by the study showed that a combination of regular exercise and vaccine independently helped ward off the consequences of severe Covid infections, including reduced hospital admissions and a smaller risk of ICU admissions, ventilation and death.

This new research shows the combined effect is even greater — by linking 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 Covid-19 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 Johnson & Johnson 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. 

The study found 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.

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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.

Prof 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 per week has meaningful health benefits in preventing severe disease, in this context against a communicable viral infection.”

The benefits

Prof Glenda Gray, president of the South African Medical Research Council, 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,” Gray said.

Dr Mosima Mabunda, head of wellness at Discovery Vitality, adds: “As the body of evidence grows, there is simply no denying the copious benefits of physical activity. Exercise improves our overall health, contributes to our quality of life, extends our lifespan and determines how healthy we’ll be in those later years.”

Discovery’s Collie explains: “In summary, our study shows that physical activity appears to enhance the protective effects of single-dose J&J vaccination against severe Covid.

“We therefore strongly recommend that physical activity should be encouraged through greater public health messaging, as a key method which reduces individual and population-wide risk of serious Covid illness,” she said.

According to the latest statistics provided by the National Department of Health, only about 2,000 Covid vaccinations were administered over the past 24 hours. DM/MC