WEAK immunity, pre-existing health conditions and lack of compliance with standard operating procedures (SOP) could be some of the reasons fuelling “breakthrough” Covid-19 infections, experts said.

A breakthrough infection refers to a person contracting a disease after being inoculated with a vaccine that is meant to prevent that very illness.

Fully vaccinated people have been reported among the new Covid-19 cases in recent days, with several of them in categories four and five, where patients require oxygen and intubation respectively.

As of yesterday, there were 34 fully vaccinated people being treated in intensive care units for Covid-19.

Their numbers, however, are far smaller than that of unvaccinated patients, and director-general of health Dr Noor Hisham Abdullah has stressed that vaccination is still effective in preventing severe Covid-19 for the vast majority.

Virologist Dr Chee Hui Yee from the Faculty of Medicine and Health Sciences at Universiti Putra Malaysia said immunity strength does play a role in breakthrough infections.

“One of the reasons could be weak innate immunity,” she said.

“Innate immunity is important for local immunity, especially mucosal immunity of the respiratory system.”

Malaysian Public Health Physicians’ Association president Dr Zainal Ariffin Omar said it is known by now that vaccination does not provide 100% protection against the coronavirus but will help reduce severe illness.

“The severity of cases will also depend on the patients’ health status, comorbidities and the strength of the infection,” he said.

He also said SOP compliance is still important even for vaccinated people while at public places.

Universiti Putra Malaysia medical epidemiologist Associate Professor Dr Malina Osman said there is a possibility that breakthrough infections could be coming from states that have been reporting a high number of cases.

Detailed information on where the breakthrough infections are from is not revealed in Noor Hisham’s daily press statement.

“In my opinion, we have to look at the data according to the states. What we have so far is a cumulative value for all patients in categories four and five,” said Malina.

“Based on the figures of current new cases, some of the states have perhaps recorded higher numbers, which reflect higher transmissions in the field.”

She said those who have been vaccinated but failed to observe the SOP may contract the virus.

While Selangor is still the state with the highest number of new infections daily, cases have also been surging in other states such as Kelantan, Johor, Kedah, Perak, Penang, Sabah and Sarawak.

Malina said this is a signal that people should be vigilant and ensure continuous compliance with SOP despite having completed two doses of the vaccines.

How to beef up immunity

Chee agreed that strict compliance with SOP is important.

“We have to rely on our own immune system to fight with all sorts of micro-organisms in the environment and future pathogens,” she said.

She advised people to eat healthy food and cut down on salt, sugar and fat, including oily and deep-fried food.

A vegetarian diet with sufficient dietary fibre, vitamins, minerals and phytochemicals could be helpful, she said.

Good lifestyle habits such as regular exercise as well as giving up smoking and excessive drinking are also beneficial.

While the Covid-19 infections reported among the fully vaccinated are often in category one and two (asymptomatic and mildly asymptomatic), there were also cases in the more advanced stages.

On deaths involving the fully vaccinated, Noor Hisham has said there have only been four out of about 13,000 Covid-19 fatalities as of August 18.

“Our recent clinical audit data analysis on the breakthrough deaths showed that of the overall 12,993 fatalities recorded, 80 had been partially vaccinated (0.6%) and four had full vaccination (0.03%),” he said.

A recent analysis by the University of California San Francisco pointed that waning immunity and contagious variants could be fuelling breakthrough infections.

Variants with antibody-resistant mutations could also be causing these infections. – August 30, 2021.