Editorial 1 : Rarest of rare risk
Introduction: Like in most pandemics, the after-shocks of Covid-19 are continuing. The most recent being Oxford-AstraZeneca’s vaccine being linked to a rare adverse side effect — thrombosis with thrombocytopenia syndrome (TTS). The company accepted that in very rare case TTS is possible.
AstraZeneca’s vaccine in India
- Manufactured by the Serum Institute of India (SII) in India and sold under the brand name Covishield, this vaccine was the workhorse in India’s Covid-19 vaccination programme.
- With nearly 1.75 billion doses administered, it was used to vaccinate about nearly 80 per cent of India’s vaccinated population.
- But, now, as per reports, the parents of a young Indian woman, deceased after receiving the Covishield vaccine, plan to file a case against the SII.
Understanding the rare side-effect
What exactly is a TTS?
- It is also known as vaccine-induced prothrombotic immune thrombocytopenia (VIPIT) or vaccine-induced immune thrombotic thrombocytopenia (VITT).
- It is a rare syndrome reported in persons who received the adenoviral vector Covid-19 vaccines (there are several) and is generally understood to result from an immune response triggered by the adenovirus vector used in the vaccines.
- Typically presenting four to 42 days after vaccination, the symptoms are on account of thrombosis formation (blood clots) along with thrombocytopenia (low platelet count).
- It’s classified into two tiers.
- Tier 1 tends to be associated with younger age groups and is marked by more severe cases with a higher risk of morbidity and mortality.
- The hallmark of Tier 1 is the uncommon site of thrombosis such as brain or gut or other rare sites of venous and arterial thromboses.
Why did TTS not observe during the vaccine trial?
- In contrast to the traditional clinical trials that follow a straightforward and inflexible three-step approach, Covid-19 vaccines took an expedited development route guided by the “adaptive and seamless” design advocated by the WHO for public health emergencies.
- Further, clinical trials are not adequately powered (statistically meaning, the probability of making a correct decision) for very rare events such as this.
Is TTS a threat?
- TTS reporting rates (cases per million doses administered per 21 days) have ranged from a high of 17.6 in Nordic countries to a low of 0.2 in some of the Asian countries and Brazil.
- The fatality rate related to TTS per million doses administered has been similarly heterogeneous — from a high of 0.6 to 1.3 in countries like Australia, Spain, France, Canada, and Italy to less than 0.1 in Asian countries and Brazil.
- In mid-2021, the WHO Global Database for individual case safety reports (VigiBase) reported 0.21 cases per 1 million vaccinated-days for embolic and thrombotic events after vaccination with Oxford-AstraZeneca, Moderna and Pfizer vaccines.
- Possible explanations for low reporting rates and susceptibility include lower overall spontaneous reporting, variations in country-specific vaccine use recommendations such as prioritising the vaccination of potentially younger and predominantly female healthcare workers, environmental factors, and ethnicity.
- South Africa was one of the earliest to announce the suspension of its use of the Astra Zeneca vaccine on February 7, 2021.
- By mid-March 2021, more than 20 European countries had decided to suspend its use, particularly among younger adults.
- Canada suspended it on March 29, and despite maintaining a stockpile of several million doses in the US, the company decided to withdraw its application to the Federal Drug Agency for its approval.
Views of agencies on vaccine safety
- Diverging views emerged between the position of vaccine safety experts who called for a pause and public health authorities managing the raging pandemic.
- Following a preliminary review of 25 such cases among 20 million vaccinated with the Astra Zeneca vaccine in the UK and the European Economic Area (EEA), the Pharmacovigilance Risk Assessment Committee (PRAC) of the European Medicines Agency (EMA) concluded on March 18, 2021 that the benefits of the vaccine in combating the continuing threat of Covid outweighed the risk of rare side effects.
- The disease itself also caused clotting problems that could result in death.
- It also called for specific information of the risks being shared widely.
- The WHO’s Global Advisory Committee on Vaccine Safety (GACVS) met on March 16 and 19, 2021.
- It reviewed available data from 20 million doses administered in Europe and another 27 million doses administered in India and similarly concluded in favour of a positive benefit-risk profile.
Conclusion: Nested within a pandemic, there are critical ethical dilemmas for the courts to resolve. The bottom-line is the WHO’s criteria for vaccine confidence — need for trust in the effectiveness and safety of vaccines and the perceived motivations of policy-makers.
Editorial 2 : Long dry spell
Introduction: While the current focus may be on elections, that may well change one month from now, when all eyes will be on the monsoon. Lord Curzon once remarked that Indian economy’s growth is a ‘gamble on the monsoon’. The back-to-back bad monsoons can have adverse effect on Indian economy.
The status of the current water level
- At 50.43 billion cubic metres (BCM), water levels in 150 major reservoirs of the country are just 28.2 per cent of their full storage capacity.
- That’s below the 62.21 BCM of a year ago and the last 10-years’-average of 52.73 BCM for this time.
- The situation is worse in the southern states, where the reservoirs are just 15.7 per cent full.
- The Nagarjuna Sagar, Somasila, Yeleru, Priyadarshini Jurala, Kaddam, Krishnaraja Sagara, Tungabhadra and Tattihallia reservoirs in Andhra Pradesh, Telangana and Karnataka have gone practically dry.
Impact of less rain on agriculture
- Last year’s not-so-good southwest monsoon as the also post-monsoon and winter season rains — courtesy of El Niño — have affected the country’s agricultural production.
- This is evidenced by government agencies procuring only about 47 million tonnes (mt) of rice during October-April 2023-24, 5.7 per cent down from the corresponding period of 2022-23.
- Wheat procurement has been sluggish, with some 21 mt bought so far and expected to only reach 26-28 mt, as against an original target of 35 mt.
- Retail prices of pulses, sugar, potato, onion, tomato and most other vegetables are ruling significantly higher than last year, which also point to poor crops.
- El Niño’s impact has been not only on rainfall, but also temperatures.
- Wheat yields in central India, for instance, have taken a hit from an unusually warm November-December, compromising the crop’s tillering and vegetative growth.
- The scorching summer right from April has been attributed to El Niño.
What is El Nino and La Nina?
- El Nino and La Nina are complex weather patterns resulting from variations in ocean temperatures in the Equatorial Pacific Region.
- They are opposite phases of what is known as the El Nino-Southern Oscillation (ENSO) cycle.
- The ENSO cycle describes the fluctuations in temperature between the ocean and atmosphere in the east-central Equatorial Pacific.
- El Nino and La Nina episodes typically last nine to 12 months, but some prolonged events may last for years.
- El Nino is a climate pattern that describes the unusual warming of surface waters in the eastern tropical Pacific Ocean.
- It is the “warm phase” of a larger phenomenon called the El Nino-Southern Oscillation (ENSO).
- It occurs more frequently than La Nina.
- La Nina, the “cool phase” of ENSO, is a pattern that describes the unusual cooling of the tropical eastern Pacific.
- La Nina events may last between one and three years, unlike El Nino, which usually lasts no more than a year.
- Both phenomena tend to peak during the Northern Hemisphere winter.
The current status regarding El Nino
- El Niño seems to be signing off, with most global models indicating it to weaken to a “neutral” phase by June and even developing into a La Niña during the second half of the four-month monsoon season (June-September).
- Given the past association of La Niña with surplus rainfall in India — the Met Department’s forecast of a “most likely to be above normal” monsoon this year is based mainly on it — that is a good augury.
Conclusion: For the government taking over post-elections, the primary challenge in its first 100 days might be to manage food inflation in the event of the monsoon turning out not so great. One must hope for the best but always prepare for the worst.