Long-Term Effects of Coronavirus, COVID Vaccines in India and Fomites Transmission Guide

For patients in Pune and across Maharashtra who recovered from COVID-19, the health journey did not always end with a negative test result. A significant proportion of individuals — particularly those who had moderate to severe illness during the Delta wave — continued to experience symptoms weeks or months after recovery. At healthcare nt sickcare, a family-run diagnostic laboratory operating in Aundh, Pune since 2007, we observed a clear increase in post-COVID blood test requests from 2021 onwards, as patients sought to understand the long-term effects of coronavirus infection on their blood, immunity, and organ function. This article addresses the most clinically relevant facts about coronavirus — including the complete list of COVID vaccines available in India, fomites transmission, long-term effects on blood clotting, and what current evidence says about post-COVID recovery.

Current corona symptoms in the Omicron-descendant era are milder on average, but long-term effects of COVID — particularly on cardiovascular health and cognitive function — continue to affect a subset of patients. The condition known as Long COVID or post-acute sequelae of SARS-CoV-2 (PASC) is now classified as a distinct medical condition by WHO.

Coronavirus Myths and Facts — Setting the Record Straight

Misinformation about coronavirus spread as rapidly as the virus itself during the pandemic. Here are key myths alongside the evidence-based facts:

• Myth: COVID-19 only affects elderly people. Fact: While older adults and those with comorbidities face higher risk of severe illness, people of all ages — including children and healthy young adults — can contract and transmit the virus. During Pune's second wave, many patients under 45 without prior comorbidities required hospitalisation due to Delta variant severity.
• Myth: Wearing a mask causes oxygen deficiency. Fact: Surgical and N95 masks do not reduce oxygen levels to clinically meaningful degrees. This has been confirmed in multiple controlled studies. Mask-wearing remains one of the simplest evidence-based measures to reduce aerosol transmission indoors.
• Myth: COVID-19 can spread through mosquito bites. Fact: There is no evidence of mosquito-borne transmission of SARS-CoV-2. The virus is spread primarily through respiratory droplets and aerosols, and secondarily through fomite contact.
• Myth: Natural immunity from infection is sufficient — vaccination is unnecessary for recovered patients. Fact: ICMR-funded studies and global data confirm that hybrid immunity — combining natural infection with vaccination — provides broader and more durable protection than either alone. Getting vaccinated even after recovery is recommended by Indian immunisation guidelines.

What Are Fomites? How Do They Spread Coronavirus?

Fomites are inanimate objects or surfaces that can harbour infectious agents and serve as intermediaries in disease transmission. Common fomites examples in the context of COVID-19 include doorknobs, lift buttons, stair railings, shared pens, ATM keypads, mobile phone screens, and shared kitchen utensils.

When an infected person touches a surface, viral particles are deposited. A susceptible person who subsequently touches the same surface and then touches their mouth, nose, or eyes can become infected. Studies published during the pandemic found that SARS-CoV-2 could survive on plastic and stainless steel surfaces for up to 72 hours under laboratory conditions, though real-world survival is generally shorter due to environmental factors including UV light, temperature, and humidity.

Fomites transmission played a particularly significant role in crowded settings — including shared transport, offices, and clinical waiting rooms across Pune and Pimpri-Chinchwad. Practical steps to reduce fomite-mediated infection include: regular disinfection of high-touch surfaces with 70% ethanol or sodium hypochlorite; avoiding sharing personal items such as water bottles and towels; using one's elbow, knuckle, or a tissue to press lift buttons and open doors; and washing hands for at least 20 seconds after contact with public surfaces.

Long-Term Effects of COVID — What Does the Evidence Show?

Long-term effects of COVID — collectively called Long COVID or post-acute sequelae — are symptoms that persist beyond 12 weeks after acute infection and cannot be explained by an alternative diagnosis. According to WHO estimates, approximately 10–30% of COVID-19 survivors experience some form of Long COVID, with higher rates observed after severe acute illness.

The most commonly documented long-term effects include persistent fatigue, post-exertional malaise (worsening of symptoms after physical or mental exertion), shortness of breath, cognitive impairment known as brain fog, headache, joint and muscle pain, disturbed sleep, and palpitations. Anxiety and depression are also significantly more prevalent in Long COVID patients, partly due to the biological effects of systemic inflammation and partly due to the psychological burden of prolonged illness.

Coronavirus Long-Term Effect on Blood Disorders and Clotting

COVID-19 has a well-documented and clinically significant effect on blood coagulation, making thrombophilic (clotting) complications one of the most serious long-term effects of coronavirus infection. SARS-CoV-2 triggers an immune response that activates the endothelium (inner lining of blood vessels) and promotes hypercoagulability — an excessive tendency for blood to clot.

Studies published in leading Indian and international medical journals during 2021–2022 documented elevated D-Dimer, fibrinogen, and C-reactive protein in a substantial proportion of COVID-19 patients even after clinical recovery. These abnormal coagulation markers are associated with increased risk of deep vein thrombosis (DVT), pulmonary embolism, stroke, and myocardial infarction. A subset of Long COVID patients in Pune and across India presented with these elevated markers weeks after discharge from hospital.

For patients who experienced moderate or severe COVID-19, a post-COVID blood test panel including D-Dimer, hs-CRP, complete blood count, and ferritin is clinically recommended to detect ongoing inflammatory or thrombotic activity. Our related article on the coronavirus pandemic in India covers the broader population-level impact in more detail.

COVID Vaccines — Complete Name List Available in India

India has one of the most extensive COVID vaccination programmes globally, having administered over 2.2 billion doses through the CoWIN platform by 2023. The following is the complete list of COVID vaccines approved for use in India by the DCGI (Drugs Controller General of India):

• Covaxin (BBV152) — Developed by Bharat Biotech, Hyderabad. Whole-virion inactivated vaccine. Approved for adults and children above 12 years. India's first indigenous COVID vaccine.
• Covishield (ChAdOx1-S / AZD1222) — Manufactured by Serum Institute of India (SII), Pune. Viral vector vaccine based on AstraZeneca technology. Most widely administered in India.
• Sputnik V (Gam-COVID-Vac) — Russian adenoviral vector vaccine. Limited availability in India through Dr. Reddy's Laboratories tie-up.
• ZyCoV-D — DNA plasmid vaccine developed by Zydus Cadila. First DNA vaccine approved for humans in the world. Three-dose intradermal administration. Approved for 12 years and above.
• Corbevax (RBD protein subunit vaccine) — Biological E vaccine. Approved for adults and children above 5 years. Used in heterologous booster programmes.
• Covovax (NVX-CoV2373) — Protein subunit vaccine by SII (Novavax technology). Approved for adults.
• iNCOVACC (BBV154) — Intranasal COVID-19 vaccine by Bharat Biotech. First approved intranasal COVID vaccine globally for booster use in India.

According to WHO and ICMR guidance, updated boosters targeting JN.1 and Omicron-descendant subvariants are recommended for elderly individuals, immunocompromised patients, and those with chronic comorbidities. Current corona vaccine availability and eligibility can be confirmed through the Ministry of Health and Family Welfare website.

Long-Term Effect of COVID Vaccine — What Is Known?

Serious long-term effects of COVID vaccines are rare, and all approved vaccines have demonstrated favourable safety profiles in large population studies. The most commonly reported post-vaccination effects — injection site soreness, mild fever, and fatigue — resolve within 1–3 days and reflect the immune system mounting a response.

The rare adverse event most associated with adenoviral vector vaccines (Covishield, Sputnik V) is Vaccine-Induced Immune Thrombocytopenia and Thrombosis (VITT) — a clotting disorder occurring in approximately 1–2 per million doses. Myocarditis and pericarditis — very rarely associated with mRNA vaccines, which were not widely used in India — are typically mild and self-resolving when they do occur. ICMR and the Indian Pharmacopoeia Commission conducted post-marketing surveillance studies confirming that the benefit-risk profile of all approved Indian vaccines strongly favours vaccination over infection-related risk for all age groups. Testing complete blood count and platelet function can help identify any haematological changes in the rare cases where post-vaccination concerns arise.

Watch: COVID-19 Testing and Post-Pandemic Health Monitoring

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