Rhinovirus;

Is it just my imagination or are Covid-19 cases going down as influenza cases are surging out of control during this flu season?

FA Manian MD, MPH, , , , , , , , Leave a comment

No, you are not imagining! Although during respiratory tract infection (RTI) season several viruses such as rhinovirus, respiratory syncytial virus (RSV) and coronavirus may cocirculate, influenza virus frequently outcompetes many RTI viruses, likely through a phenomenon called “viral interference.” 1-4

A negative viral interference is observed when a virus that has already infected a host makes that host resistant to infection by the second virus (isn’t that fascinating?). Although there a lot of virus, host and environmental variables that affect infection risk, potential mechanisms for this interference include a rapid and robust innate immune response to the first virus such as through upregulation of interferon (IFN) production which can protect against unrelated viruses, thereby creating a temporary “antiviral state.” 1-4

A negative viral interference has been shown between influenza-A virus (IAV) and SARS-CoV-2 by a cool 2024 study using the air-liquid interface culture model of the differentiated human airway epithelium. 4 Replicating IAV induced a robust interferon response and suppressed SARS-CoV-2 replication in both sequential and simultaneous infections. In contrast, SARS-CoV-2 did not demonstrate significant viral interference with IAV.  The researchers took their experiment a step further and found that oseltamivir (Tamiflu), an anti-IAV agent, restored SARS-CoV-2 replication with IAV coinfection by reducing induction of IFN!

One explanation for the inability of SARS-CoV-2 to interfere with the production of influenza virus is its slower induction of IFN stimulating genes likely due to its more effective mechanisms of antagonizing the IFN response with infected cells.4 Another explanation is that SARS-CoV-2 has a slower growth rate than IAV, making it more susceptible to being “outgunned” by faster growing viruses. Some strains of IAV may also cause more damage to the epithelial cells than SARS-CoV-2 thus reducing the number of host cells available for SARs-CoV-2 infection.2 Last, secreted IFNs (eg, IFN λ) can also bind to receptors present at the surface of infected and neighboring state blocking the second virus from infecting the host.1

So, it looks like competition among living forms in this world also applies to the world of viruses!

Bonus Pearl: Did you know that the concept of viral interference was first described in the 1960s following observation that oral administration of live enterovirus vaccines decreased detection of several unrelated respiratory viruses such as influenza virus, RSV and human adenovirus?1

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References

  1. Piret J, Bolvin G. Viral interference between respiratory viruses. Emerg Infect Dis 2022;28:273-280. Viral Interference between Respiratory Viruses – PubMed
  2. Gilbert-Girard S, Piret J, Carbonneau J, et al. Viral interference between severe acute respiratory syndrome coronavirus 2 and influenza A viruses. PLOS Pathogens 2024;20(7):e1012017. Viral interference between severe acute respiratory syndrome coronavirus 2 and influenza A viruses – PubMed
  3. Kaaijk P, Swaans N, Nicolaie AM, et al. Contribution of influenza viruses, other respiratory viruses and viral co-infections to influenza-like illness in older adults. Viruses 2022;14, 797. Contribution of Influenza Viruses, Other Respiratory Viruses and Viral Co-Infections to Influenza-like Illness in Older Adults – PubMed
  4. Cheemarla NR, Watkins TA, Mihaylova VT, et al. Viral interference during influenza A-SARS-CoV-2 coinfection of the human airway epithelium and reversal by oseltamivir. J Infect Dis 2024;229:1430-4. Viral Interference During Influenza A-SARS-CoV-2 Coinfection of the Human Airway Epithelium and Reversal by Oseltamivir – PubMed

Disclosures/Disclaimers: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

 

 

Is it just my imagination or are Covid-19 cases going down as influenza cases are surging out of control during this flu season?

Are NSAIDS contraindicated in patients with 2019 novel Coronavirus infection (Covid-19)?

FA Manian MD, MPH, , , , , , , , , , , , , , , , , 1 Comment

Despite recent internet reports of the association of non-steroidal anti-inflammatory drugs (NSAIDs) with worsening symptoms among patients with Covid-19 (1), firm clinical evidence to support such claims is currently lacking. However, there are some theoretical reasons why it may still be best to avoid NSAIDs in this condition due to their potential adverse impact on the innate and adaptive immune responses as well as their antipyretic properties (2-9).

 
Blunting of the innate immune response: Certain NSAIDs (eg, ibuprofen, naproxen and celecoxib) inhibit cyclooxygenase enzyme-2 (COX-2) and impair production of several pro-inflammatory cytokines important in fighting infections, such as tumor necrosis factor, interleukin 1 and 6, as well as interferon, an antiviral cytokine (2,6,8). COX-2 has been shown to be important in controlling viral replication in influenza (4). Ibuprofen has been associated with inhibitory effects on a variety of polymorphonuclear functions, including chemotaxis (2).

 
Impact on adaptive immune response: COX-2 inhibition may be associated with impaired neutralizing antibody production (3,4,8). Potential mechanisms include modulation of cytokine expression, nitric-oxide production, and antigen processing/presentation and T lymphocyte activation (3,8).

 
Antipyretic effect: NSAIDs are often given for treatment of fever which is an evolutionary host response to infection. A meta-analysis of animal studies evaluating the impact of antipyretics (including aspirin, NSAIDs, and acetaminophen) in influenza found lower survival in animals treated with antipyretics (9). Longer duration of viral shedding has also been associated with the use of aspirin or acetaminophen in rhinovirus infection (9).

 
Formal epidemiologic and experimental studies are sorely needed to evaluate the safety of NSAIDS in Covid-19.  

 

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References
1. Kolata G. Is ibuprofen really risky for Coronavirus patients? NY Times, March 17, 2020. https://www.nytimes.com/2020/03/17/health/coronavirus-ibuprofen.html
2. Graham NMH, Burrell CJ, Douglas RM, et al. Adverse effects of aspirin, acetaminophen and ibuprofen on immune function, viral shedding, and clinical status in rhinovirus-infected volunteers. J Infect Dis 1990;162:1277-1282. https://academic.oup.com/jid/article/162/6/1277/918184
3. Culbreth MJ, Biryunkov S, Shoe JL, et al. The use of analgesics during vaccination with a live attenuated Yersinia pestis vaccine alters the resulting immune response in mice. Vaccines 2019;7, 205; doi:10.3390/vaccines7040205 https://www.mdpi.com/2076-393X/7/4/205
4. Ramos I, Fernandez-Sesma A. Modulating the innate immune response to influenza A virus:potential therapeutic use of anti-inflammatory drugs. Frontiers in Immunology. July 2015. Volume 6. Article 361. https://www.ncbi.nlm.nih.gov/pubmed/26257731
5. Falup-Pecurariu O, Man SC, Neamtu ML, et al. Effects of prophylactic ibuprofen and paracetamol administration on the immunogenicity and reactogenicity of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugated vaccine(PHID-CV) co-administered with DTPa-combined vaccines in children:An open-label, randomized, controlled, non-inferiority trial. Human Vaccines & Immunotherapeutics 2017;13: 649-660. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5360152/
6. Housby JN, Cahill CM, Chu B, et al. Non-steroidal anti-inflammatory drugs inhibit the expression of cytokines and induce HSP70 in human monocytes. Cytokine 1999;11:347-58. https://www.ncbi.nlm.nih.gov/pubmed/30186359
7. Agarwal D, Schmader KE, Kossenkov AV, et al. Immune response to influenza vaccination in the elderly is altered by chronic medication use. Immunity & Ageing 2018;15:19. https://www.ncbi.nlm.nih.gov/pubmed/30186359
8. Bancos S, Bernard MP, Topham DJ, et al. Ibuprofen and other widely used non-steroidal anti-inflammatory drugs inhibit antibody production in human cells. Cell Immunol 2009;258:18-28. https://www.ncbi.nlm.nih.gov/pubmed/19345936
9. Eyers S, Weatherall M, Shirtcliffe P, et al. The effect on mortality of antipyretics in the treatment of influenza infection: systematic review and meta-analysis. J R Soc Med 2010;103:403-11. https://www.ncbi.nlm.nih.gov/pubmed/20929891

 

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

Are NSAIDS contraindicated in patients with 2019 novel Coronavirus infection (Covid-19)?

How does azithromycin (AZ) benefit patients with severe COPD or cystic fibrosis (CF)?

FA Manian MD, MPH, , , , , Leave a comment

AZ is a macrolide antibiotic which interferes with bacterial protein synthesis by binding to the 50S ribosomal subunit. It is often used to treat acute respiratory tract infections due to Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, as well as Mycoplasma, Chlamydia, and Legionella sp1. Although it has no in vitro activity against many aerobic gram-negative bacilli such as Pseudomonas aeruginosa, its chronic use has often been associated with a significant reduction in the frequency of disease exacerbations in patients with chronic bronchiectasis and colonization due to this organism, including patients with COPD or CF1-3.

Because P. aeruginosa is invariably macrolide-resistant, the beneficial effect of AZ in chronically infected or colonized patients must be due to factors other than its direct effect on bacterial replication.  Several mechanisms have been invoked including: 1. Inhibition of quorum-sensing dependent virulence factor and biofilm production 2.Blunting of host inflammatory response (eg, ↑IL-10, and ↓ IL-1ß, IL-6, IL-8, TNF-α, and ↓ chemotaxis); and 3. Enhanced antiviral response1.

The latter finding is quite unexpected but AZ appears to augment interferon response to rhinovirus in bronchial cells of COPD patients3.  With respiratory viruses (including rhinoviruses) causing 20-55% of all COPD exacerbations, perhaps this is another way AZ may help the host! Who would have thought!!

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References

  1. Vos R, Vanaudenaerde BM, Verleden SE, et al. Anti-inflammatory and immunomodulatory properties of azithromycin involved in treatment and prevention of chronic lung allograft rejection. Transplantation 2012;94:101-109.
  2. Cochrane review. Treatment with macrolide antibiotics for people with cystic fibrosis and chronic chest infection. Nov 14, 2012. http://www.cochrane.org/CD002203/CF_treatment-with-macrolide-antibiotics-for-people-with-cystic-fibrosis-and-chronic-chest-infection
  3. Menzel M, Akbarshahi H, Bjermer L, et al. Azithromycin induces anti-viral effects in cultured bronchial epithelial cells from COPD. Scientific Reports 2016; 6:28698. DOI:10.1038/srep 28698.

 

 

How does azithromycin (AZ) benefit patients with severe COPD or cystic fibrosis (CF)?