Impact of Antiviral Treatment Strategy on

1
Impact of Antiviral Treatment Strategy on
Hospitalization by 10 or 25 of Stockpiling of
Population (Pandemic 1968-1970)
2
Utility of NIs during Pandemic Influenza

• Reducing medical, social and economic impact of
  pandemic influenza
• Buying time before pandemic vaccine available

( Nature 2006442448-52. )
3
Recommendation for Antiviral Rx in New A/H1N1
Virus

• All datas on antiviral effectiveness, clinical
  spectrum, side effect etc are unknown
• Considered for CONFIRMED, PROBABLE
• or SUSPECTED A/H1N1 virus infection
• Should be initiated as soon as possible
• after the onset of symptoms

( WHO Report 25 April 2009 )
4
Dosing Recommendation for Antiviral Treatment of
Adult and Children gt 1 year, Oseltamivir
( www.cdc.gov/swine flu / recommendation. htm.
April 28, 2009. )
5
Dosing Recommendation for Antiviral Treatment of
Children lt 1 year, Oseltamivir (1)

• High risk of complication
• Limited data on safety and efficacy

( www.cdc.gov/swine flu / recommendation. htm.
April 28, 2009. )
6
Dosing Recommendation for Antiviral Treatment ,
Zanamivir inhaler
( www.cdc.gov/swine flu / recommendation. htm.
April 28, 2009. )
7
Recommendation for Antiviral Chemoprophylaxis in
New A/H1N1 Virus

• Household close contacts who are at high-risk for
  complication of influenza of a CONFIRMED or
  PROBABLE case
• HCWs who were not using appropriate PPE during
  close contacts with an ill CONFIRMED, PROBABLE or
  SUSPETED case of new A/H1N1 virus infection

( WHO Report 25 April 2009 )
8
Use of Oseltamivir to Prevent Influenza

• Oseltamivir administered daily for six weeks by
  the oral route is safe and effective ( 75-92)
  for the prevention of influenza.

within 7 days after their last exposure
(Oseltamivir 75 mg / d, orally, 10 days)
(Frederick HC. N Engl J Med 1999 3411336.)
9
Dosing Recommendation for Antiviral Prophylaxis
of Adult and Children gt 1 year, Oseltamivir
( www.cdc.gov/swine flu / recommendation. htm.
April 28, 2009. )
10
Dosing Recommendation for Antiviral Prophylaxis
of Children lt 1 year, Oseltamivir

• High risk of complication
• Limited data on safety and efficacy

( www.cdc.gov/swine flu / recommendation. htm.
April 28, 2009. )
11
Dosing Recommendation for Antiviral Prophylaxis,
Zanamivir inhaler
( www.cdc.gov/swine flu / recommendation. htm.
April 28, 2009. )
12
?????????????????? Pandemic Influenza
1. ??????? - ????? ?????? ????????
???????? - lab. ??????????? 2. ????? -
??????????? - ????? ?????? ????????
???????? - ???????????????????? -
?????????????????????-??????? 3. ?????????????
- Pandemic vaccine ??????????????
13
Pandemic Vaccine
14
H5 Vaccine Strategies

• 16 companies have candidate vaccines in
  development gt 40 clinical trials
• Types inactivated (whole and split virus),
  virosomal, live-attenuated
• Routes IM, intradermal, intranasal
• Adjuvants for inactivated Al(OH)3, AlPO4, MF59,
  ASO3
• Substrates for growth eggs, Vero cells, MDCK
  cells, primary monkey cells

15
Influenza pandemic vaccines

• Lag between detection of pandemic strain and full
  scale vaccine production
• Optimistic approach

16
???? - ???????? Pandemic Vaccines

• 1. ???????????????????????????????????????????????
  
• 2. ???????????????????????????????
• 3. ????????????? 2 ???????????????????????????????
  ???
• 4. ?????? antigen ??????????? ????????????????????
  ????????
• 5. ????????????????????? gt 6000
  ?????????????????????

( WHO/IVB/06.13 WHO/CDS/EPR/GIP/2006.1 )
17
Thailands Pandemic Preparedness Plan (PPP) Y2007

• 9000 million Bt. for PPP
• 1400 million Bt. for Flu-Vaccine plants for next
  5 yr.
• 2 million USD from WHO for Flu-Vaccine plant
• Plan 2 million dose production per year
• Stockpile 200,000 doses of Oseltamivir per year

18
Pandemic Influenza Medical Intervention

• 1. Pharmaceutical Intervention
• Antiviral agents - treatment, prevention
• Pandemic Vaccine - most important
• (time consuming)
• 2. Non-Pharmaceutical Intervention
• General advices hand washing
• Masking surgical mask, N95 respirator
• Social distancing

19
?????????????????? ????????????????????
??????????

• ??????? ??????? ???????
• ????????????? ???

20
Personal and Hand Hygiene in Pandemic Phase 4-6
21
Transmission of Influenza A in Human Beings

• Systemic review of experimental and
• epidemiological literatures (32 articles)
• However, we are able to conclude that
• transmission occurs at close range rather
• than over long distances, suggesting that
• airborne transmission, as traditionally
• defined, is unlikely to be of significance in
• most clinical setting.

( Lancet Infect Dis 20077257-65. )
22
In Vivo Protective Performance of N-95
Respirators and Surgical Facemask

• Surgical mask filtered out gt 95 of material
• N-95 respirators filtered out 98 of material
• Both can provide effective protection in a
• relatively low viral loading environment

( Am J Ind Med 2006491056.)
23
Mask Using in Pandemic Phase 4-6
Re-use of mask is not recommended expert in
certain situation
24
Social Distancing
25
Influenza Pandemics 21th Century
New A/H1N1 virus infection
Credit US National Museum of Health and Medicine
The Socio-economic impacts
26
First Pandemic of 21st Century

• Reach all parts of the world within 3 months1
• World Bank estimates cost to world economy US
  800 billion within a year (SARS cost gtUS 40
  billion)2
• Deaths 2 to 7 million (very mild strain,
  1968-like)3
• Severe pandemic (1918-like) 60 million deaths,
  96 of deaths will occur in the developing world4

1WHO Strategic action plan for pandemic influenza
2006-2007.2006 WHO/CDS/EPR/GIP/2006.2 2World
Bank Global Development Finance 2006 3WHO Avian
influenza assessing the pandemic threat, 2005
WHO/CDS/2005.29 4Murray et al. Lancet 2006
27
Economic Impacts of a Potential Human Influenza
Pandemic ( of GDP)
28
??????????? ????????? ??? ???????????????????? ???
?????????????????? (?????? 2550)
??????????????????????????????????????????????????
?????? 2 ????????????????? (GDP) ???????????
5.5 ??????????????? 683 ????????????? USD ( 24,
000,000, 000,000 ??? ) ????????????? ???????
??????????? 80 ???????? ?????????? ??????
67 ????????? ???????? ??????? ?????? 10
( Trust for Americans Health March 2007 )
29
Tourism in Thailand
30
Shedding of Wild-type Virus
Onset
Onset
SARS
Influenza - adult
-1 0 5 7
14 d
0 7 14 d
Onset
Onset
Influenza - children
Influenza young children
-1 0 7 10
14 d
-6 0 7 10
14 d
31
WHO Recommendation for Travel

• 1 May 2009 WHO is not recommending travel
• restrictions related to the outbreak of the
  influenza A
• (H1N1) virus. Today, international travel moves
  rapidly,
• with large numbers of individuals visiting
  various parts of
• the world. Limiting travel and imposing travel
  restrictions
• would have very little effect on stopping the
  virus from
• spreading, but would be highly disruptive to the
  global
• community.

32
New Influenza A/H1N1 Virus Prevention (1)

• Individual protection -
• 1. Masking - surgical, home made
• 2. Hand washing
• 3. Respiratory etiquette covering coughing
• Sneezing
• 4. Social distancing
• 5. Household ventilation

( www.cdc.gov/h1n1 flu / swineflu.htm. May 1,
2009. )
33
New Influenza A/H1N1 Virus Prevention

• Hospital Setting -
• 1. Triage
• 2. Patient isolation AIIR (if available)
• 3. Prioritization of antiviral agents
• 4. PPE according to risk of exposure
• 5. Patient management to reduce mortality and
• morbidity

( www.cdc.gov/h1n1 flu / swineflu.htm. May 1,
2009. )
34
Conclusion of New A/H1N1 virus

• No evidence of this virus is circulating in the
  animal population
• It was unknown of where and when the
  reassortment occured
• Ongoing study on epidemiology, clinical features,
  outcome of illness caused by this novel A/H1N1
  virus is extremely essential
• Countries that are affected by H5N1-HPAI should
  continue their activities in prevention,
  detection and control measures

35
?????????????????????? ????????????????????????
H1N1 - ????????????

• 1. Early detection - ??????????????
• 2. Early containment - ???????????? (Treatment)
• - ???????????????? (Prophylaxis)
• - ???????????????? (Vaccination)

36
Proposed Pandemic Influenza Waves
2nd
1st
3rd
4th
1-3 1-2 1-3
1-2 1-2 1-2
start
Month