Omicron

How Bad is the COVID-19 Omicron Variant? An Overview of Spread, Severity, and Vaccination Efficacy

A recent suggestion by the Technical Advisory Group of WHO on Virus Evolution led to recognizing the variety B.1.1.529 as a variant of concern, naming it Omicron (TAG-VE). This conclusion is based on data submitted to the TAG-VE indicating Omicron has many alterations that may affect its acts, such as how easy it spreads or the degree of sickness it causes. Here’s a rundown of everything we currently know.

Researchers in South Africa and throughout the world are researching to understand various facets of Omicron better, and the results of these studies will be shared when they become available.

Transmissibility of Omicron Variant

It is unclear if Omicron is more transmissible (easier to pass from person to person) than other variations, including Delta. The number of persons testing positive in areas of South Africa impacted by this variation has increased. However, epidemiologic studies determine if this is due to Omicron or other reasons.

Preliminary evidence shows that there may be a higher chance of reinfection with Omicron (that is, those who have previously had COVID-19 may be more readily re-infected with Omicron) compared to other variations of concern, but data is limited. There will be more information in the following days and weeks.

Studies Underway

WHO, at present, is collaborating with several researchers from all around the world to understand Omicron better. Assessments of transmissibility, the severity of illness (including symptoms), the performance of vaccinations and diagnostic tests, and treatment efficacy are all now at the ongoing stage.

WHO urges nations to participate in gathering and exchanging hospitalized patient data via the WHO COVID-19 Clinical Data Platform to define clinical features and patient outcomes more quickly.

TAG-VE at WHO will continue to monitor and analyze data as it becomes available, assessing how mutations in Omicron influence the virus’s behaviour.

COVID-19 Vaccine
Credit: TOI

Omicron and the World

Omicron being a COVID-18 Variant of Concern, WHO recommends countries take strict actions like improving surveillance and sequencing of cases. Countries should also share genome sequences on publicly available databases like GISAID, report initial cases or clusters to WHO and conduct field investigations and laboratory assessments to understand better if Omicron has different transmission, disease characteristics or impacts vaccine effectiveness.

Countries should continue to use a risk analysis and science-based approach to generally undertake appropriate public health interventions to limit COVID-19 circulation. In addition, they should build some public health and medical capacity to deal with an increase in instances where WHO offers nations assistance and guidance in terms of both readiness and reaction.

Furthermore, discrepancies in access to COVID-19 vaccinations need immediate attention to guarantee that vulnerable populations worldwide, including health professionals and the elderly, receive their first and second doses, as well as fair access to treatment and diagnostics.

Severity of Omicron Variant

It’s been less than a week since scientists in Botswana and South Africa warned the globe about a rapidly spreading SARS-CoV-2 strain known as Omicron. Researchers worldwide are scrambling to comprehend the harm of the variation. Omicron is already infecting more than 20 nations. However, scientists may need weeks to paint a complete picture of Omicron, including its transmissibility and severity and its ability to escape immunizations and produce reinfections.

It is unclear if infection with Omicron produces more severe illness than infection with other forms, such as Delta. Preliminary evidence shows that hospitalization rates are increasing in South Africa. However, this might be due to an increase in sick persons rather than a particular infection with Omicron. There is presently no evidence that symptoms related to Omicron vary from those associated with other variations. The first reported infections were among university students—younger people who are likely to have a milder disease—but determining the severity of the Omicron form will take days to weeks. All COVID-19 variations, including the Delta variant, widespread globally, can cause severe sickness or death, especially in the most susceptible persons. Hence prevention is always essential.

How fast is Omicron spreading?

Researchers are most concerned about the quick rise of Omicron in South Africa since it implies the variation might trigger an explosion of COVID-19 cases abroad. South Africa recorded 8,561 cases on 1 December, up from 3,402 on 26 November and several hundred each day in mid-November, with Gauteng Province, home to Johannesburg, accounting for the majority increase.

Epidemiologists track the spread of an epidemic using R, the average number of new cases caused by each illness. The National Institute for Communicable Diseases (NICD) in Johannesburg found that R was more than 2 in Gauteng in late November. That rate of expansion was last seen in the early days of the epidemic, according to Richard Lessels, an infectious-disease physician at KwaZulu-Natal University in Durban, South Africa, who spoke at a news conference last week.

Gauteng’s R-value was considerably below in September, when Delta was the prevalent strain. The cases decreased, indicating that Omicron can spread more quickly and infect more individuals than Delta. Wenseleers believes that Omicron can infect three to six times as many individuals as Delta during the same time frame, based on the growth in COVID-19 cases and sequencing data.

Although whole-genome sequencing is required to identify Omicron instances, specific PCR assays can detect a variation feature that separates it from Delta. Based on this signal, there are tentative signs that, while being exceedingly rare, incidences are increasing in the United Kingdom.

Omicron Sample
Credit: Sky News

Omicron and Vaccination

The variant’s rapid spread in South Africa suggests that it may be immune-evading. Moreover, based on increased mortality rates since the start of the pandemic, it’s likely that a considerable proportion of the population was infected with SARS-CoV-2 in earlier waves.

Omicron’s success in southern Africa might be mainly attributed to its ability to infect vaccinated patients and those who recovered from COVID-19 caused by Delta and other variations. However, the rate at which the variation spreads elsewhere may be affected by factors like immunization and past infection rates.

Researchers seek to assess Omicron’s potential to escape immune reactions as well as the protection it provides. Previous research on Omicron’s spike mutations, especially in the area that binds receptors on human cells, suggests that the variation will reduce the efficacy of neutralizing antibodies.

Effectiveness of vaccines

WHO collaborates with technical partners to better understand the possible impact of this variation on our existing countermeasures, such as vaccinations. Vaccines, notably those against the primary circulating form, Delta, are crucial for minimizing severe illness and mortality. Current immunizations continue to protect against serious illness and death.

Effectiveness of Tests

As seen with previous variants, the commonly used PCR assays continue to identify infection, including Omicron infection. In addition, there are current studies to see if there is any effect on other types of testing, such as quick antigen detection assays.

Effectiveness of Treatments

Corticosteroids and IL6 Receptor Blockers will continue to be helpful in the treatment of individuals with severe COVID-19. In addition, there will be an evaluation of other therapies to see whether they are still effective in light of the alterations to the virus in the Omicron strain.

If Omicron can avoid neutralizing antibodies, this does not rule out that immune responses induced by vaccination and past infection will not protect the variation. Immunity studies demonstrate that low levels of neutralizing antibodies may protect against severe COVID-19 infections. In addition, other components of the immune system, including T cells, may be less impacted than antibody responses by Omicron mutations. South African researchers intend to examine the activity of T cells and another immunological role known as natural killer cells, which may be especially crucial for protection against severe COVID-19.

Omicron and Effectiveness of Medical Research

There have been anecdotal reports of breakthrough infections with all three vaccinations used in South Africa — Johnson & Johnson, Pfizer–BioNTech, and Oxford–AstraZeneca. First, however, researchers will want to measure the amount of protection offered by vaccinations and past infection against Omicron.

The results are expected to be similar to how the AstraZeneca–Oxford vaccine fared against the Beta variation, an immune-evading mutant discovered in South Africa in late 2020. A medical trial demonstrated that the vaccination provided minimal protection against mild and moderate sickness. However, a real-world review in Canada revealed that immunization provided more than 80% protection against hospitalization.

Boosters and Omicron

Because of the threat posed by Omicron, several wealthy countries, like the United Kingdom, have accelerated and expanded the distribution of COVID vaccination booster doses. However, it is unknown how successful these dosages will be against this variety. The third dosage increases neutralizing-antibody levels, which is expected to offer a bulwark against Omicron’s capacity to avoid these antibodies.

Omicron and Earlier COVID-19 Variants

Early findings associated Omicron with modest illness, prompting optimism that the variation will be less severe than some of its forefathers. However, these claims, which are sometimes based on anecdotes or sparse bits of data, can be deceptive. When determining the severity of a variation, one of the most difficult challenges is determining how to account for the numerous confounding variables. These variables might impact illness progression, especially when outbreaks have limitations in geographical scenario. Reports of moderate sickness from Omicron infection in South Africa, for example, may reflect the country’s youthful population, many of whom had previously been exposed to SARS-CoV-2. During the early stages of the Delta outbreak, there were claims that the variation was causing more severe disease in children than other variants. However, this relationship was disproven as more data came in.

Omicron Infection
Credit: DNA India

Omicron Infections

Researchers will hunt for information about Omicron infections in other countries. This geographical dispersion and bigger sample size as cases will give researchers a clearer sense of how generalizable the early reports of mild sickness may be. Researchers will eventually wish to undertake case-control trials where they match two groups of individuals in terms of relevant characteristics like age, vaccination status, and health problems. Because the general hospital capacity of an area impacts the number of hospitalizations, data from both categories will come in simultaneously. Furthermore, researchers will need to account for the extent of economic disadvantage. A quickly spreading novel variation may reach vulnerable populations sooner.

Spread of Omicron

More nations are finding the Omicron variety, but the ability to swiftly sequence viruses from positive COVID-19 testing is more in rich countries, implying that there is bias in early data on the spread of Omicron. Nevertheless, surveillance efforts in Brazil and other countries are taking advantage of an expected result on a specific PCR test that might allow them to identify possible Omicron cases for sequencing. The test searches for portions of three viral genes, which encode the spike protein. Because mutations in Omicron’s spike gene impede detection in the test, samples harbouring the variation will test positive for just two genes.

Nonetheless, not everyone utilizes that test. It may be some time before there is complete mapping of Omicron’s spread. Despite some guidelines asking nations to sequence 5% of SARS-CoV-2 positive samples, few countries can afford it. Researchers are concerned that travel prohibitions imposed by certain countries on South Africa and other southern African countries in the aftermath of the Omicron finding may prevent governments from sharing genetic surveillance data.

Researchers in Bangladesh, which reads around 0.2% positive coronavirus samples, would be eager to scale up sequencing to keep track of Omicron and other developing variants. However, the resources are sparse.

Social Distancing
Credit: Health Matters

Recommended actions for Omicron Precaution

Individuals can take the most effective steps to reduce the spread of the COVID-19 virus. They should maintain a physical distance of at least 1 metre from others and wear a well-fitting mask. Additionally, they should open windows to improve ventilation,  avoid poor ventilation or crowded spaces, keep hands clean, cough or sneeze into a bent elbow or tissues and take their vaccines soon.

Based on the information given, the TAG-VE identified the new variation as a VOC. The WHO designated B.1.1.529 as a VOC, naming it Omicron. As a result, governments should undertake the following:

  • Increase monitoring and sequencing efforts to better understand SARS-CoV-2 variants in circulation.
  • upload whole-genome sequences and related metadata to a publicly accessible database, such as GISAID.
  • Use the IHR procedure to report early cases/clusters of VOC infection to WHO.
  • Perform field investigations and laboratory assessments where capacity exists and collaborate with the international community. It is to improve understanding of the potential impacts of the VOC on COVID-19 epidemiology and severity. It will also prove the effectiveness of public health and social measures, diagnostic methods, immune responses, antibody neutralization, or other relevant characteristics.

Individuals should take public health and social measures to lower their risk of COVID-19. These include wearing well-fitting masks, hand cleanliness, physical distance, enhancing ventilation of interior spaces, avoiding crowded places, and taking vaccines.

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