“Nepal has all the conditions for an Omicron surge”

The rapid spread of the new coronavirus variant Omicron across the globe has cast serious doubts about the efficacy of different Covid-19 vaccines in use worldwide. In particular, non-mRNA vaccines have been put on the spotlight, with initial lab reports suggesting their decreased protection against the new strain. 

Nepali Times spoke with regional health expert Sushil Koirala based in Bangkok this week about Omicron setting off a new surge in the Subcontinent, the danger of falling vaccine efficacy, and the best strategy for Nepal moving into 2022. 

Nepali Times: Initial lab reports suggest that non m-RNA vaccines are largely ineffective against Omicron. Would this be accurate? 

Sushil Koirala: I am not aware of any specific evidence that says viral vector vaccines are ineffective against the Omicron variant. I have also not seen any evidence of it being effective. The problem is the lack of transparency from manufacturers. That unknown, compared to some evidence we have with the mRNA vaccines, is the problem. Since little is known on the effectiveness of viral vector vaccines particularly VeroCell, the natural tendency is to think that the mRNA vaccines are a better choice as a booster against delta reinfection and Omicron variant. 

Read also: “All vaccines prevent severe Covid”, Nepali Times

In that case, how should our vaccination drive move ahead now?

Nepal should swiftly provide booster doses to the vulnerable population, many of whom were vaccinated almost a year ago. Early evidence based on lab studies shows that a recent (booster) jab provides ‘increased’ protection against Omicron. 

Most importantly, The Imperial College London Covid-19 response team has recently estimated that the risk of reinfection with the Omicron variant is 5.4 times greater than that of the Delta variant. This implies that the protection against reinfection by Omicron afforded by past infection may be as low as 19%. 

In short, there is some evidence that natural immunity from past infection and or vaccine-induced immunity from prior vaccination may not be sufficient to prevent Omicron infection. However, it’s good to point out that it is too early in the day, and there is insufficient knowledge on how those infections will translate to increased severity and or death at a population level.

Good thing is, Nepal has now received sufficient Moderna vaccines to provide booster doses to elderly and vulnerable groups and will have additional 2 million doses to continue vaccinating those of 12-18 years of age. 

Read also: Living with Covid in 2022, Sonia Awale

Is there now a clearer picture of Omicron? What can we say about a possible new surge, increased transmissibility and severe diseases?

Though it is still quite early to conclude anything, there is a broader general consensus on the following evidence: 

1) Due to mutations in the spike protein, Omicron is highly transmissible. Early studies suggest that it is four-fold more infectious than the original coronavirus and two-fold more infectious than Delta.  Lab studies suggest that Omicron was able to replicate 70 times faster in human respiratory tissue than Delta, which may help the variant spread more rapidly between people. There were also higher levels of the Omicron variant in respiratory tissue 48 hours after infection than the Delta variant. 

2) There is some evidence that natural immunity from past infection and or vaccine-induced immunity from prior vaccination may not be sufficient to prevent Omicron infection as discussed earlier.

3) There is mixed evidence based on small lab-based studies that suggest that vaccine still provides some level of protection against Omicron and while other studies suggest that there are vaccine escapes. The magnitude of either one is unknown. 

4) Early data suggests that Omicron may be milder than previous variants, but most of this anecdotal data comes from young and fully vaccinated patients. It is also important to note that many of these initially confirmed Omicron cases were already fully vaccinated or previously infected, revealing the occurrence of breakthrough reinfection and the immune escape of the Omicron variant.

5) There are not many studies/data that look at the severity of Omicron infections among unvaccinated and elderly/vulnerable people. Some experts believe that Omicron's increased transmissibility could still result in high rates of severe disease and death particularly among vulnerable and unvaccinated people. 

Read also: Masks and vaccines to stop Nepal’s 2nd wave, Sushil Koirala

At this point in the pandemic, what should be Nepal's best strategy moving forward?

We have three confirmed imported cases of Omicron. Since the first case arrived in Nepal in mid-November, it is safe to assume that there must be small cluster transmission happening in Nepal, particularly in Kathmandu. Recent superspreader political events have exacerbated the risks of the transmissions to other parts of Nepal. All three confirmed cases were detected when they were clinically sick and among vaccinated people. It shows that our active surveillance is not working well. 

Despite having multiple cases from fly-in travelers, our real risk of a large-scale outbreak is likely to come from across the southern border. So, yet again, what will happen in Nepal will largely depend on how the Omicron outbreak unfolds in India. Nepal should keep its focus on surveilling border cases and up its vaccination drive, which has flattened in recent months.  

As natural immunity seems to be unable to prevent Omicrom infections, it is of outmost importance that Nepal prepare critical care for a large-scale Omicron outbreak. 

We have a relatively lower vaccinated coverage, we have not provided booster doses,  the efficacy of the Chinese vaccine against the new variant is unknown, and public health measures at population levels are sketchy and insufficient. 

This presents all necessary conditions for a highly contagious variant to spread in Nepal. It is still too early to tell how this increased transmissibility translates to the severity and deaths. We will eventually know that, but we cannot afford to wait.

Read also: Delta variant’s wake-up call for Nepal, Sushil Koirala and Ben Ayers