What is Covid variant BF.7?
BF.7 is one of the sub-variants of the Omicron variant BA.5. It has the most potent infection ability with a high transmission rate. It is highly transmissible with a shorter incubation period and a higher capacity for reinfection, even affecting those who are already vaccinated.
When these viruses mutate, they create new lineages and sub-lineages of the SARS-CoV-2. Hence the BF.7 variant is the same as BA.18.104.22.168, a sub-lineage of the Omicron sub-lineage BA.5.
Earlier this month, a study published in the ‘Cell Host and Microbe’ journal reported that the BF.7 sub-variant has a 4.4-fold higher neutralization resistance than the original D614G variant. However, in a lab setting, antibodies from a vaccinated or infected individual were less likely to destroy BF.7 than the virus that spread worldwide in 2020.
According to a report by Hindustan Times, it has been suspected that this variant may affect about sixty per cent of people in China in the coming days. Globally the virus has vastly affected countries like the US, Hong Kong, South Korea, Japan, and Brazil.
Omicron BF.7 Symptoms
The new variant of COVID infection mainly causes upper respiratory disease, causing congestion of the throat and upper part of the chest. Other common symptoms include fever, sore throat, runny nose, and cough. In addition, some people may get stomach-related symptoms like vomiting and diarrhea. Doctors advise that getting tested immediately is essential as it can help stop the spread by ensuring early decisions on isolation and recovery drugs.
The symptoms are almost like the previous infections of Covid-19. In addition, pneumonia is another common symptom in the immuno-compromised and elderly population. The classic symptoms of Covid have been fever, chills, cough, fatigue, body ache, loss of taste and smell, sore throat, etc., but the deadly virus can at times show unusual symptoms.
While India has its Covid cases in control, people are vaccinated mainly, and there is some amount of immunity from previous infections. Therefore, it is necessary to stay aware of the familiar and unusual Covid symptoms, which may also present gastrointestinal symptoms, skin issues, or even central nervous system problems. Uncontrolled diabetes, kidney disease, and extreme weakness are some of the unusual symptoms of Covid.
Transmission Rate of Omicron BF.7
It is a new coronavirus mutation that transmits to other people quickly and has a short incubation period. As per studies, the R0 value of this mutant is about 10-18, meaning that an infected person can infect 10-18 people around the population.
But there is a more resilient sub-variant than BF.7. For example, the same study reported a more than 10-fold higher neutralization resistance in another Omicron sub-variant called BQ.1.
A higher neutralization resistance means a higher likelihood of the variant spreading in a population and replacing other variants.
People who are not immunized, people with weak immunity, elderly citizens, and children are at high risk. BF.7 has affected many countries worldwide, including the US, UK, Belgium, Germany, France, and Denmark. But it is rarely severe in countries other than China.
The UK, for instance, had assessed BF.7 as among the most concerning variants two months ago. However, it has scaled down its estimation of how serious it is.
In China, its severity may be due to a low immunity from previous infections and the type of vaccination.
The government of India and states have advised the use of masks and social distancing, particularly ahead of Christmas and New Year. The Indian government has started random testing of visitors from abroad at two per cent of all landings. Flights to and from China are already banned.
Risk of Reinfection
There has been a steady decline in Covid-19 in India, with an average number of around 129 and a daily positivity rate of 0.01 per cent, as of December 22. But recently, there has been a sudden spurt in cases globally due to the highly transmissible BF.7 strain of the Omicron variant.
Various reports also suggest an XBB variant, which is recombinant (a combination of two lineages, BJ.1 and BA.2.75) and is highly contagious.
The viruses keep mutating as they survive in nature by creating new lineages with the SARS COV 2. Thus, the BF. 7 is a sub-lineage of the Omicron BA.5.
1. Transmission dynamics of the variant
The mode of transmission, signs, and symptoms will overlap with that of the previous Covid variants.
A recent study reports that the current variants are more resistant to human antibodies than the original virus and spread rapidly.
2. Impact of social distancing measures
When a new mutant surfaces in the population, it will spread infections until we acquire immunity through infection or vaccination.
Union Health Ministry urges people to follow Covid-appropriate behavior and get vaccinated against Covid-19. They also said that the pandemic is spreading fast and urged the health officials to be fully geared up to challenge and step up the surveillance measures so that we would not be caught off-guard. The central government had briefed all state health departments to ensure proper screening of international passengers and genome sequencing.
The new variant might not have dire consequences in complete vaccination areas and where natural immunity has developed. But the elderly, the immune-compromised, poorly vaccinated, and the non-vaccinated population might be at higher risk.
Also, it is premature to predict the consequences regarding the XBB variant, as that has been a concern in India only since August 2022. The XBB variant does not possess increased severity of symptoms but has the potential to spread quite rapidly. Therefore, it is essential that we have to continue our vigilance with all these variants. India has also geared towards genome surveillance that would help identify new variants.
3. Effectiveness of existing treatments
The central and state health departments have requested that people start following Covid-19 rules and follow covid-appropriate behavior.
Experts also urge people to keep up with vaccinations, follow-up vaccinations, booster doses, use masks, avoid crowds and gatherings, test, and isolate themselves. The health authorities and experts say there is no need to panic. Still, they emphasize the necessity of following social distancing measures, getting tested, and getting booster vaccinations to contain the spread of the virus.
4. Impact of cross-immunity
Low immunity could be one of the reasons for easily being affected by the BF7 variant. In addition, some medical experts believe that a lowered immune response due to previous infections can be the main reason behind the surge in China.
Omicron BF.7 Variant in India
In India, four BF.7 variant cases have been reported till now. The first BF.7 infection in India was identified in October by the Gujarat Biotechnology Research Centre. Two cases were reported from Gujarat and Odisha. Both of them were treated successfully. These patients were treated in home isolation, and they have fully recovered. In the same way, the case in Odisha was also treated earlier this year.
India is in a much better position since the majority of us are vaccinated, and many got naturally infected with the Omicron variant only. The data about the new variant has yet to be discovered. However, it is unlikely to be a concern in India. The reason is that most of our population has two doses of vaccine and at least one or two clinical or sub-clinical covid infections.
As per data from India’s national SARS-CoV-2 genome sequencing network, BA.5 lineages accounted for only 2.5% of cases in November. Currently, a recombinant variant of XBB is the most common variant in India, accounting for 65.6% of all patients in November.
The Indian SARS-CoV-2 Genomics Consortium (INSACOG), in a weekly meeting, reviewed the data of genomic surveillance of variants and found that, at present, Omicron and its sub-lineages are the predominant mutations that are circulating in India.
Omicron and its sub-lineages continue to be the dominant variant in India. However, the “BA.2.75 sub-variant has acquired more mutations in spike protein and other genes of the SARS-CoV-2,” It also mentioned that the variant is being closely monitored.
Efficacy of existing vaccines
Experts believe that it is not the high level of transmission or evasiveness of the BF.7 variant to immunity that led to increased cases in China. Instead, an immune-naïve population drove it to a high number of cases.
In India, the Omicron wave was mild because the population was double protected with previous infection and vaccination. However, during the Delta wave (of April-May 2021), many people died, but those who survived had better immunity. On top of that, Omicron mainly affects elderly victims, but we considerably have a younger population.
It is why even the highly transmissible variants have not increased the caseload, with most cases recovering after a few days of fever, cough, and sore throat.
The virus has mutated since the beginning of 2020, and the Omicron variants easily escape the immune response provided by most vaccines currently in use.
Indeed, India’s Omicron wave infected many people who were already double vaccinated. That is why many companies have developed bivalent vaccines to provide better protection. However, until the Omicron wave, the vaccines could control the spread of the infection, but after that, the vaccines were not even able to stop transmission.
The mRNA vaccines have proved to be more successful than the dead vaccines used in China. There has been frequent debate about whether the efficiency of vaccines is better than the others. But the situation in Hong Kong proves that people who received the mRNA vaccines fared better than those who received the dead virus vaccine.
Omicron BF.7: Precautions
As the year-end celebrations are around the corner, it is more vital than ever to follow Covid-rules. The basic steps can help prevent the spread of possible infections.
It is winter, and the common cold, cough, and fever are other seasonal illnesses in India. But it would help if you did not ignore these symptoms. So if you or someone around you experiences the symptoms mentioned above, get a Covid test done immediately and practice self-isolation.
The first and foremost precaution people must take is wearing masks in crowded areas and taking booster doses. Covid vaccination and booster shots can help prevent complications of the subvariants. In addition, the health ministry has advised on many preventive strategies.
With the holiday season around the corner, people with low immunity should be extra cautious. They must first maintain proper hygiene. Test-Track-Treat-Vaccinate is another strategy to mitigate the Omicron BF.7 variant risk.
Although there is little increase in the cases, there must be continued surveillance to keep track of existing and emerging variants. It is also reported that random sample testing for coronavirus would be conducted at international airports on passengers arriving from China and other countries.
Omicron BF.7 Variant Severity
The severity of illness in the case of BF.7 is not higher. However, the real worry is the sheer number of people it can infect, as the spread is much faster, making early detection and isolation even more critical. The recovery rate is high, but deaths in absolute numbers may increase if the reach is more than that of earlier variants.
While many such variants can evade the acquired immunity obtained from previous infection or vaccination, no other variant after the delta variant has shown a high mortality rate. A recent study suggests that BF.7 could dodge immunity even for people vaccinated twice.
In the present scenario, China is challenged with the biggest Covid surge the world has ever seen since 2019. Though there is no official data from China, a study has reported a recording of 10 lakh cases and 5,000 deaths daily.
Impact of asymptomatic infections
The BF.7 variant is not severe but has a fast transmission rate. Even if the infected person is asymptomatic, the person can transmit the virus to another 10 to 18 people.
Immunity from infection is short-lived for coronaviruses, unlike measles or chicken pox viruses. Newer Omicron sub-lineages can leap past the immunity generated by older versions of the same variant.
The longer we are past the recent infection or the last vaccine dose, the more the number of susceptible people in a region. Many people need to follow basic precautions, making the virus spread faster. The public must understand that the virus has not gone away.
India has seen very few cases in recent times. Therefore, we cannot predict how the new omicron BF7 will affect the population in the upcoming days and months. But it is essential to be more vigilant and follow COVID-appropriate behavior such as wearing masks, social distancing, and hand hygiene.