Coronavirus: Omicron BA.5 strain is associated with higher odds of reinfection, claims study

New variants of Omicron have been emerging ever since the third wave of the COVID eased down a bit. The most prominent strains of the Omicron right now are the BA.4 and BA.5 variants.

These variants have aroused interest in researchers to study the distinct symptoms shown by them during infection, the nature of the virus and the degree to which it can harm a human body.

Several studies have discussed the severity and the nature of the infection by these variants.

A recent study has claimed that the BA.5 strain of the coronavirus' Omicron variant is more likely to cause reinfections than the other variants.

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This study has been done by a team of researchers from Portugal. The study is based on a comparative analysis between Omicron BA.2 and Omicron BA.5. "Using electronic health records and SARS-CoV-2 laboratory surveillance data, we conducted a case-case and a cohort study covering the period of Omicron BA.2/BA.5 lineage replacement in Portugal, to compare vaccine effectiveness of complete primary and booster dose against infection, COVID-19 hospitalization, and mortality," the research paper says.

The study included 27702 COVID positive cases, out of which 15396 were with the BA.2 variant and 12306 with the BA.5, between April 25 and June 10, 2022.

The study result claims that higher odds of reinfection were observed in BA.5 cases compared with BA.2.

"The protection against reinfection was inferior in BA.5 cases when compared with BA.2. Among those infected with BA.5, booster vaccination was associated with 77% and 88% of reduction in risk of COVID-19 hospitalization and death, respectively, while higher risk reduction was found for BA.2 cases, with 93% and 94%, respectively," the study says throwing light on the severity of the Omicron BA.5 strain. It also sheds light on the immune evasion property of the virus.

There were 106 COVID-19 hospitalizations and 42 deaths during the study period.

On the risk of hospitalization and death among vaccinated and unvaccinated, conditional on being infected with BA.5 or BA.2, the study found that BA.5 cases vaccinated with booster had 3.4 times higher odds of hospitalization compared BA.2 cases, which again was a strong evidence supporting the immune evasion nature of the virus.

The Omicron BA.5 strain was first detected in South Africa in February 2022, following the detection of BA.4. In cell cultures, BA. 5 and BA.4 replicate more efficiently and are more fusogenic. "Fusogenic properties and serine protease TMPRSS2 usage by different variants can explain the ability to infect lower respiratory cells," says the study.

Though there are no distinct symptoms associated with BA.5 variant, the COVID symptoms which one should be aware of are:

• Loss of smell and taste
• Feeling of congestion or suffocation
• Sore throats
• Persistent cough
• Runny nose
• Fatigue; extreme weakness
• Common cold like symptoms

COVID is known to put an impact on other body organs as well though it is widely considered as a respiratory illness only. Soon after the second wave of COVID, several cases of COVID complications came to the fore where individuals had other health complications due to COVID.

COVID affects the heart in a devastating manner. Arrhythmia, palpitation are commonly seen in COVID patients. Even in those who have prior heart complications, the condition can worsen due to a COVID infection. COVID can also affect liver, kidney, and lungs.

Long term COVID or the long COVID has an adverse effect on the mental health and cognitive functioning of human beings.

The pandemic is still critical for us. It is not the time to drop the guards. Wearing masks, remaining well informed of the infection in vicinity and also remaining updated with the symptoms are the only ways we can save ourselves from the infection.