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Despite our hopes, the Covid-19 pandemic is still ongoing. In England, there has been a 10% increase in hospital admissions and the largest rise in cases is in the north. Due to reduced testing and paused national monitoring and infection surveys, we have less data on Covid-19 than in previous months. The virus continues to mutate and we are aware of potential situations that could lead to new and harmful variants. However, with limited surveillance on emerging strains and their spread, we are losing our ability to closely monitor the situation in real-time.

It is becoming more difficult to determine which variations are causing the increase in cases. Recent estimates indicate there is a mixture of several variants, including some that originated from XBB last year, as well as EG5.1 (Eris) and a small amount of BA.2.86 (Pirola), both of which were discovered in the last few months. It appears that this virus is constantly evolving, and new data released in the past few days reveals that the Pirola variant, which is derived from XBB, has undergone further changes and may have a higher level of immune evasion.

What causes this virus to mutate rapidly? As viruses reproduce at a high rate, they are more likely to undergo genetic mutations. This means that the more infections there are, the higher the chances of the virus mutating. Some countries, like the UK, have chosen to coexist with the virus without implementing measures such as testing, ventilation improvements, and mask-wearing. Additionally, limited vaccine coverage and access to booster shots increase the likelihood of more Covid infections and further mutations of the virus.

A possible explanation suggests that when individuals with weakened immune systems contract an infection, there is a higher likelihood of dangerous variants arising. This is because these patients may struggle to fully eliminate the infection, leading to the virus persisting at low levels and mutating over an extended period. It has been speculated that the BA.2.86 (Pirola) subvariant, which bears similarities to previous BA.2 Omicron subvariants, could have evolved from viruses that persisted in an immunocompromised individual and underwent significant changes over time. Similar theories have been previously proposed for other concerning Covid variants.

New evidence suggests that the medications used to treat Covid can also contribute to changes in the virus itself. A recent study on the antiviral drug molnupiravir revealed that it works by causing mutations in the virus’s genetic makeup, which can hinder its ability to function properly and combat the infection. While the goal is to prevent the spread of these mutated viruses, a group of scientists and citizens in the UK found through sequencing data that this is not always the case. The mutations caused by molnupiravir are different from the ones typically seen in Sars-CoV-2 evolution, so it may not necessarily lead to more dangerous variants. Nevertheless, we must be mindful of the potential for drug resistance to arise, similar to how antibiotic resistance develops.

The utilization of Molnupiravir in the UK is not as extensive compared to other countries. However, it’s worth noting the disparity in access to antiviral and monoclonal therapies. For instance, the United States has widespread usage of antiviral drugs, while some countries allow these drugs to be purchased without a prescription. On the other hand, many middle-income countries have limited access to these treatments. This has resulted in an uneven distribution of medication and the potential for excessive use of certain drugs. This can lead to increased viral resistance, the development of more dangerous variants, and lack of necessary treatment for those who need it the most.

The current approach in the UK of relying solely on vaccines for vulnerable populations is not sufficient. Even with booster shots, not everyone will have a strong response to the vaccine, especially those with compromised immune systems or taking medication that affects their immune function. Individuals at a higher risk of contracting Covid should have access to well-regulated treatments such as monoclonal and antiviral drugs to increase their chances of fighting the virus and prevent the development of new variants. However, in reality, access to these treatments in the UK is inconsistent. There is a “Goldilocks effect” where patients must be sick enough to qualify for the drug(s) but not too sick that the drugs would no longer be effective.

There are over 500,000 individuals in the UK who are medically at risk. One person shared that they would feel more confident if there was a backup plan in case of infection, but the availability of treatment is unclear. This person feels that the responsibility for their health lies solely on them. It is crucial to have a global plan that addresses these disparities and evaluates the usage and prescribing of medications that can benefit those who are most vulnerable.

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  Sheena Cruickshank holds a position as an immunologist and professor of biomedical sciences and public engagement at the University of Manchester.

Source: theguardian.com