Omicron BA.4 and BA.5: Transmissibility & Symptoms

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Omicron BA.4 and BA.5 are two of the most recent subvariants of Covid-19 to be detected.

These two subvariants were first detected in South Africa in the early months of 2022. Each variant appears to be an offshoot of the previous BA.2 variant.

How Transmissible are Omicron BA.4 and BA.5?

A virus’s basic reproduction number (R0) is the average number of people an initial case can infect in a population with no immunity, either from vaccines or previous infection. The original Omicron strain (BA.1) had an R0 of 9.5. BA.2, of which BA.4 and BA.5 appear to be offshoots, was estimated to be 1.4 times more transmissible than BA.1.

Studies from South Africa suggest that BA.4 and BA.5 may be more transmissible than BA.2. So BA.4 and BA.5 could be the most infections variants of Omicron yet.

On top of this, these variants appear to be good at evading immunity. This means there’s a greater chance of reinfection with these strains compared to previous strains.

What Are The Symptoms of Omicron BA.4 and BA.5?

Like previous Omicron variants, BA.4 and BA.5 brings numerous flu-like symptoms. These include:

  • Coughing, sneezing, and a blocked or runny nose
  • Aches, pains, and fatigue
  • Sore throat and a hoarse voice
  • Chills, shivers, and fever
  • Loss of smell, or an altered sense of smell
  • Tight chest and shortness of breath

Preventing and Controlling Omicron BA.4 and BA.5 Infection

Data from South Africa and the UK suggest that BA.4 and BA.5 waves may not be associated with an increase in severe disease and death.

Nonetheless, this highly transmissible strain may still pose a risk to elderly and immunocompromised people, and to people with certain underlying health conditions. On top of this, extensive infections may place a further strain on an already overburdened health service.

Strategies for Preventing the Spread of Covid-19 Variants in Healthcare Settings

We’ve put together an essential guide to preventing the spread of Covid-19 in hospitals and other healthcare settings.

Strategies include:

  • Standard infection control precautions, such as effective hand hygiene and good respiratory and cough etiquette.
  • Effective PPE use, including proper protocols for putting on and taking off equipment.
  • Cleaning for infection prevention and control, with specific procedures depending on the setting.

Read our full guide to preventing the spread of Covid-19 in healthcare settings.

Air Filtration for Effective Infection Control

Like the previous variants, BA.4 and BA.5 are airborne viruses. A recent report from the University of Cambridge demonstrated how an air filtration system in a Covid-19 ward successfully removed almost all traces of the airborne virus.

In public and communal areas of healthcare settings, including waiting rooms, canteens, wards and corridors, air filtration systems can make a huge difference in preventing the spread of BA.4 and BA.5. They trap and kill viruses, bacteria and other harmful particles while quietly filling rooms with cleaner, healthier air.

Our range of HealthProtect air purifiers can completely filter the air in a room as large as 62m² once every 12.5 minutes. The advanced filters can trap up to 99.97% of particles down to 0.1 microns, and up to 99% of viruses and bacteria – including the BA.4 and BA.5 Omicron variants.

We can help you in your fight against Covid-19 and other respiratory viruses this winter and beyond. Get in touch to talk to one of our infection control experts today.